Genetics

As you all know and appreciate, one of the major differences between The Sims and The Sims 2 is the genetic traits that can be passed to the children such as hair colour, eye colour, skin tone and personality. 

When you are creating a family in the game, you can create a male and female adult couple and then you can click on the little soother icon to create a baby, child, teenager or another adult that carries a mixture of those two original adult Sims. If you don’t like the first mix, you can always try again. However, when you are playing the game and a couple of Sims have a baby together, you have no control over the genes of the baby. The newborn baby will have a mix of the parents’ traits, but, as in real life, there are some dominant and recessive genes.

Every Sim has two genes for eye color, hair color and skin color. One of them is dominant and the other one is recessive. The game pre-determines what genes are dominant or recessive. For hair, black hair is dominant over all other hair colors. Brown hair is dominant over blonde and red hair. Blonde and red hair have the same level of dominance so the hair color of the baby of a blonde Sim and a red-haired Sim will be determined randomly. In eyes, brown, dark blue and alien eyes are dominant over green, light blue and green eyes. In skin tone, there is a slight difference though. If a Sim with dark skin has a baby with a light-skinned Sim, the baby can have dark, medium, tan or light skin because the game does not consider any of the skin tones as dominant. Instead the game tries to mix the skin tones of the parent Sims. With the alien skin however, there is a slight difference. It is mostly dominant to other skin tones, but, if the baby has one alien and one human parent, it can present normal skin tone and can carry the alien skin tone to the next generations as a recessive gene.

The genetics also apply in personalities of the Sims. When you create a Sim, he or she will have 25 personality points, whereas a born Sim has 35 personality points. When a Sim is born, these points are distributed mainly according to one of the parents’ traits but in some cases they can be distributed randomly.

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Facial features are also included in the genes of Sims. For example, the size of nose, eyes or cheeks of parent Sims can affect the facial features of the baby. However, facial features do not work like skin tones. If a parent has big cheeks and the other has skinny cheeks, the baby has either big or skinny cheeks, it won’t have medium size cheeks.

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There is one thing players should be careful with: some townie or NPC Sims might have different traits than their visible ones. For example, a blonde policewoman may not actually have blonde genes. You can usually spot this bug when you try to change their appearances and notice that the eyebrow color is actually different than their hair color.