A Look at Genetics in The Sims 3

Note: I have not found any facts about the genetic system from someone who specifically worked on it, so I will use what is showcased in the game alongside with some comparable examples. Also, there may be inaccurate information though I really did try my best in researching. Some conclusions are just my own interpretation of how I think something works compared to how it may actually work. I am not a biologist or geneticist. Regardless, this sort of subject matter is both fascinating and fun for me. I will share what I learned in case someone may find this just as intriguing.


Case Study 1: The Rumbaa Family

Nathaniel and Trinity are founders I created in CAS and they have 15 in-game born children. From the oldest to the youngest are: Jonathon, Carlston, Genesis, Paige, Ryne, Hunter + Choice (Fraternal Twins), Velvet + Jules (Fraternal Twins), Dallin, Faith + Ryin (Fraternal Twins), Alex, Madison and Olivia.

(Sidenote: The first and second pair of twins I used a mod to get but left the gender selection at random. The third pair of twins happened without my intervention, if I remember correctly.)


Figuring out the parent’s genotypes and the children’s phenotypes using the Punnett Square

By having children, it may be possible to figure out the parents’ or founders’ genotypes in order to see the possibilities of the phenotypes they may produce. Of course not all possibilities may be shown such as codominance or incomplete dominance when using the Punnett Square.


Nathaniel and Trinity Possible Hair Color Genotypes and Their Children’s Possible Phenotypes


More or Less.

50% chance for inheriting Brown hair and is heterozygous like the parents.
25% chance for inheriting Black hair and is heterozygous like the parents.
25% chance for inheriting Blonde hair and is homozygous recessive.

(Since more children have brown hair, it makes sense to count Brown-black over Black-brown.)



To determine the accuracy in percentages, it is best to go by in-game data. Of all the Rumbaa children:

9 children have brown hair.
5 children have black hair.
1 child has blonde hair.

Which translate to:

60% chance of a child coming out with brown hair.
33.3% chance of a child coming out with black hair.
6.7% chance of a child coming out with blonde hair.

Each time a child is born, those percentages may change and needs to be recalculated.

To find the statistics for your Sim’s offspring then count all the children and that will be the denominator. Count how many children have x hair color and y hair color and z hair color if applicable. Turn each statistic into a fraction and then reduce if necessary. There are 9 children who have brown hair out of 15 children altogether. So I get 9/15 which reduces to 3/5 then use long division which I got 0.6 then 0.6 X 100 = 60. You can use any calculator for the quick answer as well.

Nathaniel and Trinity Possible Eye Color Genotypes and Their Children’s Possible Phenotypes


11 children with green eyes
4 children with blue eyes

73.3% chance for green eyes
26.7% chance for blue eyes

Skin Color



Skin color, like hair color, is a polygenic trait meaning there are multiple genes that determine the color. There is such a broad range in skin colors all around the world, so it is nice to see TS3 does this rather well and is a huge improvement and advancement compared to TS2 limited presets. All 15 children vary from light to dark and showcases TS3 ability to handle offspring of parents who have different skin colors.

Sex Determination

9 sons
6 daughters

60% chance for a son
40% chance for a daughter

Only women have an X-chromosome and men have either X or Y chromosome to determine the sex of the baby at conception. I think this is also the case in TS3 and the sex is locked in place at conception.

XX = Female and XY = Male

The 3rd Generation: Grandchildren

Note: Some things may change as the generations grow and I am sure new discoveries to be observed. So my Sims possible genotypes and phenotypes are educated guesses of what I currently know in-game.

Carlston married Starr and they have five children with one on the way. They have four daughters and 1 son. From oldest to youngest: Carlie, Starrlah, Bumi, May and April. May is the only child, thus far, who inherited her grandmother’s hair color. It is likely Carlston has the Brown-black genotype as his dominant and recessive genes. May’s genotype is presumably Black-brown. Starr’s parents’ both have brown hair and her little brother also has brown hair. I think Starr has Brown-brown.

80% chance for brown hair
20% chance for black hair


60% chance for brown eyes
40% chance for green eyes


80% chance for a daughter
20% chance for a son


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Genesis married Angelica and they have five children with one on the way as well. They have four sons and one daughter. From oldest to youngest: Gene, Kin, Chancelor, Keenan and Angel. Some family members dye their hair but everyone’s original hair color is preset black. I have made it a habit to keep track of hair colors so it will not be an issue if the child takes a dyed hair color.

100% chance for black hair
Angelica’s parents both have preset black hair and her little brother too.
(Sidenote: I do not know which recessive gene Genesis carries but figure it is between brown or blonde. I will not possibly know until the children grow up and have children of their own who they may pass the recessive gene down to. Unless the parents' end up having a child with brown or blonde hair.)


60% chance for blue eyes
40% chance for green eyes


80% chance for a son
20% chance for a daughter


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Paige married Obi and they have 7 children. They have 4 sons and 3 daughters. From oldest to youngest: Reuben, Amelia + Leo (Fraternal Twins), Rebecca, Ace, Natalie and Jai.

57.1% chance for brown hair
42.9% chance for light golden brown hair


50% chance for green eyes
50% chance for light gray eyes
Jai has not aged into a toddler yet.


57.1% chance for a son
42.9% chance for a daughter


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Ryne has an ex-girlfriend named Raini and they have 3 children together, 2 sons and 1 daughter. From oldest to youngest: Deanna, DeMario and Harley.

33.3% chance for black hair
33.3% chance for blonde hair
33.3% chance for brown hair
(Of course these percentages may change if they were to have more children together. It would be possible for a light golden brown hair color as well.)


33.3% chance for light gray eyes
33.3% chance for blue eyes
33.3% chance for green eyes
(Of course these percentages may change if they were to have any more children together. Not likely though. But so far out of all the families I have, they have children with two different recessive hair colors.)


66.7% chance for a son
33.3% chance for a daughter


Ryne has a recessive hair color for black (his mother’s hair color) and Raini for blonde (randomly selected as she and her brother, Obi, are founders but that doesn’t mean Obi has a recessive trait for blonde hair too since siblings can carry different recessive genes). Ryne and Raini have two different recessive traits though it is said there must be two matching in order for a child to get a recessive hair color.

However, genetics are not so simple. I figure because heterozygous genotypes exist then this is what may happen as a possibility. Sometimes there are surprises in the genetic lottery such as this case. Genetics can pick and choose as long as there is a possibility for such an outcome. Of course not all outcomes may show up within one generation or possibly even the next. In this example, either black or blonde gets a chance in the inheritance pool. For the parents, black and blonde are recessive but for a child who inherits, one of those becomes their dominant while the other they become a carrier of to possibly pass down to their future child or grandchild. Maybe even further down the line of descendents.

I figure it is Ryne who a recessive trait for black hair because Hunter, his brother, has blonde hair that is a different root, base and highlight color than Harley’s. They only match in tips but nothing else. So I doubt this variation of blonde is Ryne’s parents’ recessive blonde, therefore must come from Raini. If these two in the future find a new romantic interest then it may be possible to further investigate their recessive hair colors with any other children they might procreate.

Hunter (Uncle)
R: 200, 185, 150
B: 225, 210, 170
H: 215, 205, 180
T: 200, 190, 155

Harley (Nephew)
R + H: 170, 150, 95
B + T: 200, 190, 155

Nathaniel and Trinity have 20 grandchildren with 2 on the way to add up to 22. Their oldest grandchild is Gene but no start yet on the 4th generation. But Chancelor has a promised wish to get married and both of his parents have a wish to see him get married. I am letting my Sims choose their own love interests and sometimes it takes awhile before they find someone they connect to. Or at least someone they thought they connected to. And sometimes they choose the same sex which is frustrating as a family-orientated player who loves playing with genetics. But I tend to have large families so the genetics will continue to play out in each generation.

Case Study 2: Different Levels of Melanin

The Yamazaki Family
(Sidenote: Kiba uses a non-default skin and because of the lightness of it, it may affect any chances for incomplete dominance or this couple just doesn't have a high percentage chance for incomplete dominance for skin color in their genes like Nathaniel and Trinity.)
(Sidenote 2: Kiba and Simone are founders and created in CAS while Yoshi and Naomi were created as teens using the Play with Genetics feature from Kiba and Simone. The other four children were born in-game.)

Kiba and Simone are married with 6 children. They have 4 sons and 2 daughters. One of their daughters, Megumi has a lighter shade of black (60, 60, 60), close to jet black, than her father’s pure black hair (0, 0, 0).


Megumi’s Approximate Hair Color Compared to Her Father’s


These instances of the same hair color but varying in lightness or darkness may be associated with imitating different melanin levels of eumelanin and pheomelanin.

Eumelanin is responsible for creating black or brown color. If there is little of this melanin present in an individual then their hair color will be light and can consist of many color variations of blonde. If there is a lot of this melanin present then the hair color will be dark and consist of many color variations of brown or black.

Pheomelanin is responsible for creating red or orange color. Those with orange or red hair can have varying amounts of eumelanin which results in different hair colors such as auburn or strawberry blonde.

As mentioned before, like skin color, hair color is a polygenic trait.

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This is an old CAS Play with Genetics Test.

Mother ‘s Hair Color
R: 48, 38, 28
B: 97, 56, 23
H: 120, 74, 43
T: 74, 48, 30


Father’s Hair Color
R: 40, 40, 40
B: 65, 65, 65
H: 36, 36, 36
T: 62, 62, 62


Child 11’s Hair Color
R + H + T: 150, 110, 75
B: 150, 95, 50


Because his hair is orange and his mother's is brown and his father's is black then this must be a recessive hair color of one of them.

Child 3 has a different variation of black than her father's
R + H + T: 40, 40, 40
B: 70, 70, 70


Child 10 seems to have a darker color of a recessive blonde based on the root color from her siblings with blonde hair. So melanin levels can also affect recessive hair colors too in TS3. Fascinating. Also, because child 10 has a lighter black root hair color than her father's but a darker blonde recessive base hair color then technically that's an example of codominance besides differing melanin levels in recessive hair colors. So one parent has blonde and the other has orange recessive hair colors.
R: 60, 60, 60
B: 70, 60, 40
H + T: 50, 40, 20

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Another Play with Genetics Test

Father
R: 123, 67, 19
B: 171, 93, 35
H: 190, 116, 58
T: 194, 119, 56


Mother
R: 48, 38, 28
B: 97, 56, 23
H: 120, 74, 43
T: 74, 48, 30


Son


Daughter


The children’s hair color is:
R + H + T: 150, 110, 75
B: 150, 95, 50


One of the parents has black as a recessive trait and I think purple eyes is a mutation? Though I read that purple eyes do exist but rare based on lack of melanin in the iris and how light is reflecting from the blood vessels in the eyes which gives off a purple hue. If I even remember that correctly. I guess it may be associated with albinism but don't really know. I am starting to wonder if a mutation chance is higher or lower in some Sims. Perhaps there is a lot of information that gets randomized once a Sim is created. How much hidden Sim Data could one Sim have?


During other test and examples of families living in the Sim world, some Sims do not create children with varying lighter or darker colors, as in, strictly either the mother’s or father’s hair or skin color exactly. However, other Sims it seems, have genes showcasing a chance for incomplete dominance and a chance for lighter or darker versions of the parent's hair color or recessive hair color(s).

Are there hidden hair color presets that are rare to see or are these actually being calculated in some way from a hidden gameplay mechanic? Maybe a bit of both? Either way, it seems to happen under certain conditions in order to see these types of unique hair colors. I suspect there may be more of those.

Does hair color blending exist in TS3 but just rare depending on the coupling and genes? It definitely seems that way. Like a box of chocolates, you never know what you are going to get but at the same time makes sense and follows something based on reality. I am going to take an educated guess the genetic system is based on more than just the principles of inheritance by Gregor Mendel.

“Our modern understanding of how traits may be inherited through generations comes from the principles proposed by Gregor Mendel in 1865. However, Mendel didn't discover these foundational principles of inheritance by studying human beings, but rather by studying Pisum sativum, or the common pea plant.”

“Today, whether you are talking about pea plants or human beings, genetic traits that follow the rules of inheritance that Mendel proposed are called Mendelian.”

(https://www.nature.com/scitable/top...nheritance-593/)

Case Study 3: Breaking the Family Tree

The Rumbaa Family – Genesis Rumbaa - 2nd Generation

Genesis and his wife Angelica live in Roaring Heights. Nathaniel and Trinity, Genesis’s parents’ live in Moonlight Falls while Francesco and Alexandria, Angelica’s parents’ and younger brother Keanu are currently in the library waiting for the next round to be moved into Roaring Heights. Currently they are both disconnected from the 1st Generation. When the family tree is intact and all are in the same neighborhood I know there is a chance for a grandchild to inherit a grandparent’s hair/eye color, but what happens when the grandparents are not present because you move the 2nd Generation to a different neighborhood, thus breaking the family tree?


There are two methods which lead to the same results.

Method 1: CAH (Create-a-Household)

I used NRass to take Genesis and Angelica into Stylist to save them to the CAS bin then exited out to enter CAH in Edit Town. Once in CAH I opened up the saved Sims bin to retrieve the two Sims and then proceeded to Play with Genetics. The children came out with black being the most common, blonde and orange hair. There was no preset brown among the genetic calculator which is Genesis’s father hair color.
So to answer the question I posed to better understand the implications of my chosen playstyle, the answer is: The game appears to be coded in a way that grandparents must be present in the same neighborhood in order for there to be a possibility of a grandchild to inherit their hair/eye color. The grandparent’s dominant genes become non-existent and no longer included in the gene pool with any family unit who is disconnected.


Method 2: Instant Baby (NRass Master Controller)

As mentioned before, this replicates the same results as method 1 and this can be taxing and crash the game. I tend to get more stable results when I keep the game on pause when I do this. However, I would not recommend this method.



Recessive Genes

To refresh, recessive genes are those that one is a carrier of but does not have, but can pass the gene(s) down to their child either as a carrier or inheritor.
The grandparents’ hair/eye color will not have a chance to get passed down to descendants when the family tree becomes incomplete, however, their recessive genes do which seem to imply the game is coded to specifically use the hidden assigned recessive gene(s) in addition to inheriting grandparents’ hair/eye color when the family tree is intact. Otherwise, when the family tree becomes fragmentary, only the recessive genes will continue through the generations regardless of the condition of the family tree.


The 1st Generation Recessive Hair Colors

Trinity and Nathaniel produced children with Black, Blonde, Brown and Orange hair. Francesco and Alexandria produced children with Black, Blonde and Orange hair. In order to attempt to get the Punnett Square accurate, I have to use trial and error based on in-game data, but there is still quite a bit of guesswork. Meaning I know which couple has which recessive hair/eye colors, be that as it may, there is no known way of pinpointing which recessive hair/eye color is whose. All I know for certain, is both Blonde and Orange are the known recessive hair colors that can be passed down to the 2nd generation and so on.


Certain genes get turned on or expressed while the rest is turned off or unexpressed. Basically when the genetic calculator chooses between the father’s or mother’s or grandfather’s or grandmother’s or recessive hair/eye color for the offspring. So many possibilities can carry different genetic information that can result in similar looking siblings to siblings who look nothing like each other to descendants with an unexpressed hair/eye color from a previous generation.


The Possible Genotypes and Phenotypes of Genesis and Angelica

(Now I know the game is not coded to count the grandparents hair/eye color as recessive, but will have the extra genetic information to choose from when considering the phenotype of connected families. I will have to revise the Punnett Squares to reflect this new discovery.)


(However, since I cannot figure out for certain which recessive gene is whose in some or most cases, then I will carry on in a different approach without the Punnett Square. For example, when one or both Sim(s) is/are known to have more than one recessive gene for hair/eye color then it gets especially complicated not being able to know for certain which Sim has what. It would have been nice to have options, thus control over recessive genes being chosen by the player using CASt to pick or create any color besides an option to choose randomly from the CAS hidden presets. Also, that up to 3 different variations of the same hair/eye color could also be incorporated such as one parent having 3 different shades of blonde hair and 2 different shades green eyes or none at all and another parent having different 2 different shades of brown hair and 3 different shades of grey eyes. And of course, on top of that, up to 3 different recessive hair/eye colors. That seems to be the case in TS3 but just not player controllable unfortunately.)

I know you're looking into hair and eyes but it's striking how persistent grandma's jawline & cheekbones are.

Yes, it is interesting to see which facial features and body types get inherited through the generations as well. Genesis's children mostly take after their mother's facial features. There are so far two out of six of their children who inherited a more rounded face.

Angel (Natural hair color is preset black)
-Mother's eye shape
-Father's eye color
-Mother's nose
-Mother's lip shape
-Closer to her father's skin tone
-Father's rounded face
-Curvier physique than her mother (Though lately I notice she autonomously will work out so her weight changes a bit.)
-Smaller breast than her mother but that may change when she ages up



Dimitri (Currently a toddler but aged up to see what he would look like.)
-Mother's eye shape
-Father's eye color
-Father's nose
-Father's lip shape
-Closer to his mother's skin tone
-A slight mix between father's round face and mother's angular face


There are some really unique mixtures of parents genetics but I do not see those type of genetic calculations as often as I would like.


I suspect just like recessive hair/eye colors that sometimes these kinds of combinations can be rare to come across. Especially, if one of the parent's facial features and/or body type is more prominent. Perhaps if both parents' genetics are balanced out with each other then maybe more intermixing may take place in their offspring.

Case Study 4: Multiple Recessive Genes in the Pool

The Fleming Family – 3 Known Recessive Hair Colors – 3 Known Recessive Eye Colors

Estevan and Robin are elders when I recently saved them to the bin, but in no way should it affect the results, seeing that the game does save the original hair color before they age up and using a mod to allow elder pregnancy will use their original hair color for offspring, if not recessive.

These are the 3 recessive hair colors I have come across from the pairing of Estevan and Robin.


Black


Blonde


Orange



These are the 3 recessive eye colors which I didn’t print screen from play with genetics, but I did with the descendent which share the same recessive hair and eye colors as their founders.

Green-blue


Grey


Blue



Starr, Estevan and Robin’s daughter, and her husband Carlston’s play with genetics test.

Blue


Green-blue


Grey



Black


Blonde


Orange



There can be more than 2 recessive genes for the same trait in the gene pool, such as eye color. What is the max number? I do not know but my guess is 4 based on if the father inherited two different recessive genes for the same trait, one from each parent. And if the mother also inherited two different recessive genes for the same trait, one from each parent. Then the pairing would increase what is possible within the gene pool as the generations go on.


So after having investigated the founders, I can accurately tell which recessive genes are in the pool for the descendants to possibly inherit.

So far out of 5 children in Carlston and Starr's family unit, only one child has come out with a recessive gene for black hair. Initially I thought the child inherited her grandmother’s hair color but when I took a closer look, it did not match her grandmother’s preset black and was instead the recessive black from her mother’s side.

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On a different note, of course it is known that there is a possibility for Sims to inherit genetics from their grandparents. But what I find interesting is that this test I did with one of the play with genetics children has an eye shape that is very similar to her grandmother’s. However, the grandparents are not currently in the world, so I wonder if this recessive eye shape is a part of Carlston’s DNA without the need for his mother to be present to add more to the gene pool. Perhaps, facial and body genetics from the grandparents, if different, are saved as recessive genes to possibly pass down to a descendant.


I think this concludes recessive hair and eye colors as I do not think there is anything else for me to investigate. At least not until I get around to great grandparents or even great-great grandparents to see if I also notice any inheritance from those generations but I think great grandparents might be where the game draws the line in remembrance for memory sake is my educated guess.

In a nutshell: Recessive genes in TS3 is a hidden gameplay mechanic that is randomized for the founder(s) and shows permanence throughout the descendants inheritance out of the luck of the draw. As far as I know, it cannot be manipulated until it becomes a dominant gene, but even then that will not stop the chance of it showing up, unless perhaps with a mod to strictly allow only dominant hair and eye colors from the grandparents or parents. But me, I enjoy diversity so it is a very much welcomed feature to me in TS3, though it would have been nice to pick and choose the recessive genes I want for my Sims to have the creative freedom as well.

Now, I guess I will take a closer look at my Sims facial and body genetics. I think the Okotie-Eboh family will be good for that since I notice quite a bit of variance in their offspring.

ewww heterosexual couples

That's really unhelpful in the context of this thread.

The Okotie-Eboh Family

Thus far, altogether, Kibwe and Fatima have 12 biological children and 1 adopted daughter for a total of 13 children. So here are the combinations of the gene pool from the founders in order from oldest to youngest.

Abeni
She looks like her mother, similar to her younger sister, Awa, but has their Dad’s skin tone and hair color. It would be nice to have seen more variation in facial appearance, than just copy and paste.

Abeni’s Physique
She resembles her mother’s physique. Another copy and paste type genetic roll of the dice.


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Chi
I wanted to do something different since TS3 does not have any feature pertaining to genetic conditions such as albinism. Chi is the only albino in the family.

Chi’s Physique


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Tendai
Originally, he had that mutated yellowish-green hair color. When that happens in my game, I decide on a new hair color from either the parents ‘or grandparents’ expressed traits, if different. In this case, I thought he looked nice with brown hair but instead of an exact replica, Tendai has matching brown eyebrows and facial hair.

Tendai’s Physique


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Kanyin
I do not recall if I altered him after Play with Genetics.

Kanyin’s Physique


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Akachi
I do remember that Akachi is based on an older version of Kibwe, but I liked how he looked so kept him when I finally put together the Okotie-Eboh family.

Akachi’s Physique


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Udo
Udo is also based on an older version of Kibwe, if I remember correctly. He was the only child who came out with blue eyes in Play with Genetics and I decided to keep him.

Udo’s Physique


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Leone
He was born in-game as well as all his brothers and sister after him.

Leone’s Physique


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Chad

Chad’s Physique


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Maya
She is the adopted daughter of Kibwe and Fatima. I took her into CAS to give her a unique look so she doesn’t look like the typical randomly generated preset Sim. Everything is pretty much the same when the social worker brought her home except her face and a darker black hair color.

Maya’s Physique


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Sudan

Sudan’s Physique


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Dumisani

Dumisani’s Physique


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Awa
As beautiful as she is, like her mother, she is like a clone, since there is little diversity between them. Sure the phrase comes to mind, “You sure do look like your Mom.” Or “I can see you definitely take after your father.” Perhaps the developers took that too literally, although I am sure there are many who could pass for their parent’s twin but maybe it being too common may not be as welcomed in a life simulator. I don’t think it shouldn’t happen but rather happen a lot, well…less.

Awa’s Physique
A comparison shows that she is slimmer and a bit muscular than her mother.


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Dakarai
He is the second born fraternal twin after Awa and like how she looks like their mother, he looks like their father. At least there is some kind of difference with hair/skin/eye colors/body type which helps to get away from an identical image.

Dakarai’s Physique
Like most of his brother’s, generally speaking, they take after their father’s naturally muscular frame and muscle definition.


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These are the different outcomes in facial looks and body types I have noticed thus far.
-Clone of one parent
-Clone of one parent with differences
-Combination of both parents
-Combination of one parent or both parents with unexpressed feature(s)
(Such as a trait inherited from grandparent(s) or unknown ancestor, like a different eye shape than either parent. < Not shown in those above concerning a different eye shape but I have seen this with a different couple using Play with Genetics. But yes I do notice that eye, lip, jaw shapes can all look different on the opposite gender. < Now that is shown above to a certain extent.)

*These genetic comparisons are not necessarily the Sims actual ages in-game.

The Okotie-Eboh Family: Gen 3

Currently, Abeni has three children with her husband, Myles. Starting from the oldest to youngest are:

Minnie
Both Minnie and Jacqui inherited their grandmother’s hair color. Other than that she pretty much resembles her mother.


Minnie’s Physique


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Jacqueline
Jacqui mostly takes after her father’s genes with a much narrower jawline.


Jacqueline’s Physique


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Milo
A combination of some traits from his parents.


Milo’s Physique


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Chi has six children with his wife, Jean, and two permanent foster children. Originally, the biological children looked different than they do now. One of the reasons being, when Chi met Jean they both were teenagers and she was the babysitter, who eventually I changed her face because it started to annoy me with the typical randomly generated look. So after changing her face that meant I also had to update and change her children faces as well. Starting from the oldest to the youngest are:

Zaire
He has his grandmother’s hair color. I figure people with albinism can still pass on recessive genes inherited from their parents. If they inherited albinism then that has become their dominant and expressed genes, but what about the many other genes for melanin to possibly pass down to their children? So far, I read that parents with albinism had a child not displaying any albinism. Either this is an exception to the rule since genetics is complex or possibly they had two different types of albinism which would result in children with more melanin. Also some people with albinism and without expressed albinism/carrier can have children with varying skin tones and hair/eye colors among some being born with albinism depending on what's in their gene pool. Back to the game's genetics, the skin colors of Chi and Jean's children are the same they were born with after I changed it again, some eye/hair colors have been changed if they have light skin closest to their father or if Chi's version of blue eyes didn't make sense to me. Realistic or not, I think this may be my final edit.


Zaire’s Physique


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Jodi
Jodi and her brother, Ren both were taken by the social worker for neglect by their parents. (And because my Sims lived on the same apartment lot, the social worker grabbed all the children.) So I quit without saving and I had Chi and Jean care for them. At the time, they only had Zaire and Cairo. It was quite hectic with four toddlers but Chi seemed to love them as his own, while Jean took time to adjust before she started bonding with them on her own. She was so stressed initially, lol.


Jodi’s Physique


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Cairo


Cairo’s Physique


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Ren
I changed his facial sliders a bit because while some sliders look fine to the extreme on some Sims, it doesn’t always translate so well on the opposite gender.


Ren’s Physique


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Nakuru



Nakuru’s Physique


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Somalia
She is the first of the triplets and the first time, if I recall accurately, that I ever had triplets in TS3 and I’ve been playing since 2009, lol. Somalia looks a lot like her dad though she does have a combination of features from both parents, his features transfer uniquely on the opposite gender.


Somalia’s Physique


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Kenya
She also has her grandmother's hair color and has her grandfather's eye color.


Kenya’s Physique


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Sahara


Sahara’s Physique


Now I have to get used to their new looks all over again.

In the case of the Japanese/Ethopian founders, I noted where their cursor is. Now Kiba has a custom Asian skin that is light to light-medium tones only, however his cursor is more to the right and his wife's cursor is a bit to the left from his. So as I look and compare the two, there isn't much room for skin blending since both are within close proximity.


The founders original skin tone values.


Now if Kiba's cursor was further to the left then there should be more opportunities for varying skin colors. So let's test that theory.


So that is the reason why there is little to no skin blending for the Yamazaki family. Now that I know, I'll try to keep this in mind for future Sim founders that just because a custom skin ramp is mostly light or mostly dark, doesn't mean the game picks up on that but rather the placement of where the cursors are in relation to each other. The further apart they are, the more variation there will be and the closer they are, the less to no variation there will be. Which is something already known but I got thrown off by the overall lightness of this custom skin ramp, however it still works the same as the game's genetic calculator. Now my curiosity when asked, "Why doesn't this family have skin blending like the other one?" was piqued and now I am able to answer accurately based on in-game data. And hopefully this helps anyone else who may have run into the exact situation and now knows why.

Which Genetic System Is Your Favorite? TS2 or TS3

The Sims 2

Dominant Hair Colors
-Black
-Brown

Recessive Hair Colors
-Blonde
-Red

Dominant Eye Colors
-Brown
-Dark Blue

Recessive Eye Colors
-Green
-Light Blue
-Grey

In addition, dominant traits play a role in facial features that can be viewed in SimPE. Any dominant genes will be inherited over any recessive genes within a dominant/recessive pairing. Otherwise any dominant/dominant or recessive/recessive pairings the genes the child(ren) inherit will be randomly chosen.
Skin colors have incomplete dominance, meaning a child can inherit a blend of the parents’ skin tones based on the four skin tone presets available.


The Sims 3

“Dominant” and “Recessive” genes still exist but as far as I know, cannot be viewed externally such as TS2. However, there is evidence based on the Play with Genetics feature and through the observation of in-game generations.

-All hair and eye colors can be considered dominant or recessive regardless of dark vs light colors.

-Dominant and Recessive have a completely different meaning, in fact, I prefer using Expressed (Dominant) and Unexpressed (Recessive). An expressed gene is any gene that shows up on a Sim. An unexpressed gene is one that the Sim is a carrier of, thus does not show on the Sim. Unexpressed genes are randomized upon the founder(s) creation.

-Unexpressed genes are always the same but colors can vary in shade and new unexpressed genes can be introduced into the gene pool through a lover. There is even a possibility for a Sim to be a carrier of more than one unexpressed gene for a given trait. Such as being a carrier for both blonde and red hair. Furthermore these traits even will survive a broken family tree because that particular information stays with the Sim to pass onto their offspring as either an expressed or unexpressed trait.

-Facial features, physique and weight are also incorporated into expressed and unexpressed genes.

-Some genes have a higher percentage of getting inherited than others but typically does not dominate other genes 100%. However, there are exceptions in TS3 and also in real life where some genes are very strong and regardless of color.

-Skin colors also have incomplete dominance and can blend.

-Each pairing can have a variety of differences when it comes to inheritance percentages and patterns.


Real World Genetics

According to https://learn.genetics.utah.edu/content/basics/patterns

“Dominant and recessive inheritance are useful concepts when it comes to predicting the probability of an individual inheriting certain phenotypes, especially genetic disorders. But the terms can be confusing when it comes to understanding how a gene specifies a trait. This confusion comes about in part because people observed dominant and recessive inheritance patterns before anyone knew anything about DNA and genes, or how genes code for proteins that specify traits.”

“The critical point to understand is that there is no universal mechanism by which dominant and recessive alleles act. Dominant alleles do not physically “dominate” or “repress” recessive alleles. Whether an allele is dominant or recessive depends on the particulars of the proteins they code for.”

“Dominant phenotypes are not always more common than recessive phenotypes”

“Recessive alleles can be present in a population at very high frequency. Consider eye color. Eye color is influenced mainly by two genes, with smaller contributions from several others. People with light eyes tend to carry recessive alleles of the major genes; people with dark eyes tend to carry dominant alleles. In Scandinavia, most people have light eyes—the recessive alleles of these genes are much more common here than the dominant ones.”

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In other genetic study articles, some prefer to use terms such as expressed and unexpressed traits than dominant and recessive traits because it depicts an accurate description than saying certain traits will always overpower over some others.

There are many real life examples of genetics but here are some:
https://www.youtube.com/watch?v=P2NPaKskGj0

Tracing the Red Hair Gene through Our Family Tree: A Relatable Review of How Red Hair is Inherited
https://www.youtube.com/watch?v=R5xdbhW_O6s

https://www.youtube.com/watch?v=JIUK2KSbvvI

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For me, TS3 is my favorite portrayal of the genetic system because it is realistic, complex and has a lot of creative freedom with the RGB/HEX/Color Wheel. Though I do wish there was an option to chose my own unexpressed hair and eye colors with the RGB/HEX/Color Wheel.

Hmm, well I discovered, though it is still randomly chosen, the genetic system can use any saved preset eye colors to use as an unexpressed trait for the founders. I had a bunch of custom eye colors saved then but not anymore because there were just too many bogging down CAS. It also might be possible that once the player inputs a custom saved preset that the game may save it in its own data bank for possible use later.

I created two different families as a challenge to see how long it would take for me to get a child with an unexpressed trait from each family. And when the children are older to pair them off as long as one of them have an unexpressed trait inherited from their parents. The first family, El-Hashem, have 5 children and one on the way. Their first born, Baha, got an unexpressed trait. Their second born, Farah, got her parents expressed traits. Their third born, Dania, got an unexpressed trait and she's the one I will choose to pair up with the chosen son of the other family. The fourth and fifth children are twins.


The second family, Mwangi, have 6 children. The first and second born are fraternal twins, Tatianna, got her parents expressed traits and the second born, Sienna, also got her parents expressed traits. The third born, Taz, got an unexpressed trait from his parents. The fourth, fifth and sixth child are triplets and only Marlyn got an unexpressed trait from his parents.


So Dania and Taz will have an arranged marriage in the future. These two I randomized their personality traits and found it interesting that both rolled the Insane traits. That's a trait I rarely, if ever, play with so it's already been interesting to see how this trait helps to bring out more uniqueness in their personalities. Currently they are both children so it's going to be awhile until they are older.


Taz eyes are a custom color that was saved. It's brown-purple or purple-brown which are the preset eye colors mixed together.


This was a personal challenge to myself and surprisingly it didn't take as long as I thought it would so that's great. It's also an experiment of playing a bit differently and further expanding the knowledge of what the genetic system is capable of.

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Edit: Here are some of the other children since in a different save I aged them up to young adults, not only to see what they would look like but also to fill out my family tree ahead of time with their photo.



Edit 2: I also really like how the genetic system doesn't always create a mid-tone blend between both parents skin tones. As I read and hear some people say of multi-ethnic children are 50/50 which I feel in some cases is false. From what I understand of the basics of genetics is that there is 100% of complete DNA from both the mother's and father's genetic information, provided all is well.

Now when a child is conceived I suspect the instructions can take any varying percentage and genetic information from each parent. So for example a child could get 86% of genetic data from one parent and get 14% from the other parent. By the way that is my genetic makeup. Also, I don't look "mixed" according to what most view the definition and appearance as. I notice there is a misconception from some that children always look mixed which is false and not how genetics work 100% of the time. A person can have light skin or dark skin and be the product of two different skin tone parents. They might just have a higher parentage from one parent than the other but are still considered multi-ethnic.

Miles Morales is a fictional character, yes, one of the many who is Spider Man across the spider-verse. He has a mother who is Puerto Rican and a father who is African American and although he looks African-American, he is still multi-ethnic or specifically bi-ethnic, who has a higher percentage from one parent than the other. And to figure how realistic that is, my mom is Spanish/Native American or something like that and my father is African American but I look African American. So yes, there are real life examples of everyday genetics. And a lot of fictional characters who ever the writer, in most cases, seems to know the basics too. Like the example all the way from the first post of this topic of why Violet is the only one, thus far out of her siblings, to have inherited natural black hair when her mother has brown hair and her father has blonde hair.

This is what I love so much about TS3 genetic system. The developers did their homework. ❤️

A general response to: "The Sims 3 genetics is so unrealistic". 👁️👄👁️

But what about real life?

https://www.youtube.com/shorts/3yChuz79euo
https://www.youtube.com/shorts/px1FbtQQxgA
https://www.youtube.com/watch?v=QQkvIZnqcaI

The children of parents who are of different skin tones/ethnicities can take more after their mother, or their father, or more of a blended genetic makeup from both parents. What does "mixed" even look like? I want to reiterate.

Another general response to: TS3 does not have "dominant/recessive traits" (expressed/unexpressed genes) but also this happens from time to time in everyone's unmodded game. I wonder why my Sims child comes out with a hair/eye color that neither parent has? That is not what dominant/recessive traits are...right? Because TS2 genetic system is totally accurate and factual just like real life...right?
https://www.youtube.com/shorts/418UuspP_DE
https://www.youtube.com/shorts/avYr-KggLeM
https://www.youtube.com/watch?v=46mhiiGOZHo
https://www.youtube.com/shorts/ik4q86gfAHo

You know I never knew I had reddish-brown hair until my classmates bought it up and asked if I dyed my hair and I am like, "I am 11 years old, why would my mom let me dye my hair? No, my hair is not dyed." Though I did use those temporary hair dyes as a kid that lasted a few days or until you washed it out but that was pretty obvious like the color gold or silver though. Then when I was much older another classmate pointed out that I had red hair but by that point I had become aware of it. I do not know anyone in my family with red hair, however my grandmother told me we have a lot of diversity in our family including Irish. So maybe it was from my Irish ancestor and that red hair gene just got passed down to me. But to be honest, that red hair gene could have come from anyone so I have no idea. I only guess Irish because typically Irish has one of the most highest percentages for the red hair gene.

Genetics are not only complex but it is quite fascinating. The Sims 3 does an amazing job at replicating real life genetics even though some people do not understand the basics of biology/genetics because if they did then they would know.

https://www.youtube.com/watch?v=UOYF2HatbFI

Everyone's life experiences will be different so I didn't really have any identity issues growing up but then again maybe because society just looks at me and says, African. No I didn't say American at the end of that because that's my nationality, though actually I am African-European according to my DNA. I do not have any Native/Indigenous in my blood and if so then very little but from word of mouth my mother told me that her great grandmother told her that we come from two different tribes. My mother's great grandmother were full-blooded with hair so long it literally touched the floor is what I was told. According to what is online, it states that the Cherokee and Blackfoot tribes were enemies but also says sometimes tribes would basically have a truce sometimes whether temporarily or permanently. I wonder what happened? I am a sucker for love stories, is it a love story? Maybe an act of unforgettable kindness? Maybe because it is better to work together than against each other and now there's a even stronger alliance?

From what I recall most who saw my mother and I when I was in school would ask if that was my mom and I never understood that question. I understand it now because apparently it seems so difficult for some to believe that I could be a child of a woman who is light-skinned while I am dark-skinned. No one ever bullied me or said mean things because my parents were two different ethnicities and skin colors except one time in class a boy got mad because I rejected him and called me a zebra and said that's why your mom is white and your dad is black. Like that's supposed to be an insult? My mother's skin tone has never been an issue, I just cared that she loved me and she did and I loved her too. I grew up appreciating everyone's differences. Unfortunately, the world doesn't always treat people with kindness or respect just because they are a different skin color/ethnicity(ies). Racism will always exist and while it is something I never want to go through again, I know that is unrealistic. They are lost.

Anyway, yeah I agree with the child who says, "A thousand percent a person." 👍

Imagine a life simulator that got that in-depth from various human experiences. Sure it would be sad and even maddening but also would be more open-ended for story-telling. Or I mean specifically A.I. story driven. Like: My Sim is in love but the person they are in love with has a racist family but wait their family is racist too. What do they do? Okay now that's starting to remind me of a book a read with a Romeo and Juliet twist.

Not sure I'm the right person to talk about skin color inheritance/blending IRL because I live in a 99.9% white country and it's uncommon to see any black or mixed people. It's a little more common to see them in the capital or big, touristy cities. Most non-whites are foreigners. We've had an influx of Russian-speaking immigrants from the former Soviet republics and recent refugees from Ukraine. It won't change the racial make-up of my country, because Ukrainians and most inhabitants of the former Soviet Union are white.

I'll focus on hair and eye colors. My cousin and her huband both have brown eyes, but their 3 children have blue eyes. They must have inherited them from their grandparents. I don't think there's any point going into details about genetics, because it's common knowledge that there exist dominant and recessive traits and that a newborn inherits from their parents and sometimes they look more like their father but or a mother. In my the Sims 3 game the inheritance system works better than the vanilla one because of mods. A couple of years ago without the mods it sucked. I used to have sims who would inherit the whole face from one parent and the exact hair color from one of the parents. Sometime a "mutation" would creep in which resulted in the creepy pink eyes and/or shitty brownish/yellowish hair color. There was no proper variation, so I had to download mods to improve it. Now the hair and skin colors are blends and the facial features are a blend too. The only thing which didn't change is the eye color. Now I don't see any copies/clones in my sim families but sims who resemle their parents but they don't look exactly like them.

You should add berry sweet genetics, I often do

A lot of my sims have weird hair, skin, and eye colors

I almost never do normal sims

The point is that it is not common knowledge and that is why some claim TS3 genetics is unrealistic and is confused by "random" hair/eye colors which neither parents and/or grandparents have. Expressed genes are those visually present and unexpressed genes are those that are not visually present but is apart of the DNA to pass down to their child who will either inherit the unexpressed gene which will become apart of their phenotype (visually seen), or inherit the unexpressed gene as part of their genotype (not visually present).

When comparing with real life examples, it is shown how accurate TS3 is compared to TS2. I am not using any genetic mods because but I do not have many issues with how genetics work in the game except the mutated hair color which I change to either the parents or grandparents hair color or blend between the parents. And the frequent clone of one parent is annoying but that is easy to rectify by taking the parents into CAS and re-rolling a child until I get an unique blend or just not a clone to replace the in-game Sim. I would rather to do this manually than add a mod that would possibly just bog down my game, especially with how many kids my Sims autonomously has.



The mutation hair color I still do not get what that is supposed to represent in the real world so I tend to just ignore it and override with my own hair color of choice. The pink/purple eyes I do not recall ever getting in-game but from what I understand that is meant to imitate the genetic condition ocular albinism for those that eyes reflect pink or purple, though other eye colors that has minimal pigment could also be indicative if the other signs and symptoms are present.

According to: https://sims.fandom.com/wiki/Genetics

"Genetics in The Sims 3 are much more simplified." False.

"There are no dominant and recessive genes, and the game simply combines features of the parents, pulling occasionally from earlier generations such as grandparents. There is a very high mutation (e.g. two dark-haired parents having a child with blonde hair, even though nobody in their family has that hair color) rate of 10%, which can be lowered to a more reasonable rate using mods."

When a child inherits the recessive trait/unexpressed gene, then that becomes their dominant/expressed gene and is not a mutation. The same process as in real life. TS2 version of dominant/recessive traits is partly inaccurate as a couple who is a dominant and recessive pair could only produce children with dominant traits which in real life is false.

TS3 does not have a real hair dye system, thus overwriting their DNA and plastic surgery does the same unlike TS2. Unrealistic sure, but another way for a player to change their Sim without the initial CAS being permanent which is more versatile and something I agree with than being too restrictive. However, if there was an option for both then that would be best. Otherwise it's now possible to change the DNA of your Sim and leave it more open-ended. If I want to keep track of my Sims natural hair/eye colors then I can do that manually and just change the child's hair/eye color if anything different is inherited.

https://www.youtube.com/watch?v=1O040-M2aJI

So it seems some do not have that common knowledge of basic biology. You can read it repeatedly over the years how many say how unrealistic TS3 is and how TS2 genetic system is realistic. Though it's a game so both has it's share of realism and fiction.



I am the opposite and prefer realism; I am not really into fantasy type play in TS3 though I enjoy the fantasy genre in books such as The Legend of Drizzt. In the future I would like to try out genetics in pets but have not got around to that yet.

Actually now that I think of it, fantasy often uses natural colors and medieval/old Europe aestethic. It does not usually do berry or banilla sweet colors - which is more associated with anime stylization.