People Who Weren't Raised by Their Natural Parents Very Early in Life

As we describe here, we seek mates who have different immune system genes from our own. However, it appears that if you weren’t raised by your natural parents very early in life, our DNA matching process probably won’t work with you. By very early in life, we mean between the time you were born and the time you reached the age of weaning. In humans, weaning age is approximately one year old, though some experts believe it’s closer to two years of age.

This information comes from two studies published in 1988, one led by Beauchamp and the other by Yamazaki, that showed the phenomenon in mice. In the experiments, newborn mice were removed from their natural parents within 16 hours of birth. They were transferred to adoptive parents, who had just had their newborns removed from them. They were nursed by their adoptive parents and then weaned and removed from them at three weeks of age. They were kept away from potential mates until sexual maturity—3 ½ months at the earliest.

When they were free to select partners to mate with, the mice based their mating preferences for different immune systems not on their own immune system genes, but on those of the parents who raised them—even if they were adopted. In other words, the adopted mice didn’t prefer immune systems that were different from their own—they preferred mates who had different immune systems from the parents who raised them.

So, these experiments indicate that very early in life—from soon after birth until natural feeding of mother’s milk stops, well before sexual maturity—the mouse’s genetic mate preference is imprinted on its brain.

If it’s true in humans, and you were given up for adoption soon after birth, or you weren’t raised by your natural parents in the first year-or-two of your life, then you may not enjoy all the benefits of our chemistry matching system.