Donor Egg: Is Intelligence Really Genetic?

When hopeful parents decide to use an egg donor, we encourage them to look for someone who fits well into their family. Many of the intended parents we work with have impressive academic backgrounds. As they face the reality that they are "losing" a genetic connection to their child, they look for an egg donor who is also a high achiever. This sometimes prompts questions around education, achievement, and intelligence: is intelligence passed down genetically?

Setting the Record Straight
First things first: Each parent’s top priority when searching for an egg donor should be finding a woman who is healthy and happy to donate her eggs. But we know it’s natural for parents to want to see themselves in their children. As a complex part of human cognition, intelligence is impacted by both genetic and other factors. So how does the intelligence of parents impact the intelligence of a child? Donor Concierge’s founder, Gail Sexton Anderson, shared the short answer: “In most cases if we take an egg from a reasonably intelligent female, fertilized by a reasonably intelligent male, you will have an intelligent child. This child will then be raised in a family of high academic achievers and is likely to do very well in this environment.”The long answer? It’s complicated!

We went straight to the experts – Genetic Counselors Gena Shepherd and Emily Mounts of ORM Fertility. They’ve broken it all down below!

Our clients often seek donors with high academic achievement. Should they be concerned with the heritability of intelligence?
Gena and Emily:
“For many years, scientists have attempted to crack the genetic code of intelligence—a lofty goal, as even defining the concept of intelligence is challenging. Most complex traits like intelligence are multifactorial, meaning that both genetic and environmental factors contribute to differences between individuals.

To determine how our genes influence multifactorial traits, scientists often turn to twin and adoption studies. Identical twins share the same environment and virtually 100% of their genes, while fraternal twins share their environment, and about 50% of their genes. If a trait is highly genetic, identical twins should share that trait (ex. high IQ) more often than fraternal twins. Adoption studies examine whether children who are adopted have traits that are more similar to their adoptive parents (environment) or their biological parents (genetics).

Twin and adoption studies have led researchers to believe that about 50% of the variance in intelligence is due to inherited genetic factors, while the remaining 50% is related to differences in environment (eg. parenting, education, home and school environment, access to resources, nutrition).(1)

There are likely hundreds, if not thousands, of genes that all have a small effect on intelligence, most of which have not yet been identified. (1) Considering the number of genes involved, as well as the influence of non-genetic factors, it is unlikely that genetic testing will be able to accurately predict intelligence at any point soon.

Intelligence is correlated with high academic achievement; however, multiple other multifactorial traits likely also play a role, including self-motivation, emotional intelligence, personality, and curiosity. (2) Some studies have indicated that high academic achievement may be even more “heritable” than intelligence alone.(2) However, academic achievement is also known to be influenced by many socioeconomic factors including income and financial security, access to education, opportunity, perceived social status/class, and privilege. (3) ”

Our take? Smart egg donors come in many forms – that may be an ivy-league donor, someone who left school and started her own business, or maybe an egg donor with a master’s degree. Each of us is unique in our experience, and our intelligence is shaped by more than our test scores and the school we attended. Our goal is to help you match with an egg donor who fits into your family, and who is healthy and willing to undergo the egg donation process. We have decades of experience guiding parents on their egg donor search, and we know we can find you the best egg donor for your family.

References:

  1. Genetics Home Reference. Created May 2015. National Institute of Health. Accessed June 2020.
  2. Krapohl E, Rimfeld K, Shakeshaft NG, et al. The high heritability of educational achievement reflects many genetically influenced traits, not just intelligence. Proc Natl Acad Sci U S A. 2014;111(42):15273-15278. doi:10.1073/pnas.1408777111
  3. American Psychological Association. Created July 2017. Accessed June 2020.