Science Vocab: Heritability

Here’s a pop quiz. Read the following statements and select the best answer from the choices below.

A: Snoring runs in my family; it is genetic.
B: Snoring runs in my family; it is heritable.

1. Statement A is true
2. Statement B is true
3. Both Statement A and B are true
4. Neither Statement A or B are true
5. Don’t know

The answer: Only Statement B can be true. Heritability deals with the likelihood or probability of traits running in families. But here is the catch: something can be heritable due to genetics or environment. In this case the environment includes culture or habits and behaviors that you experience and accept as a normal and everyday. Everything that shared among related individuals isn’t necessarily because they share the same genes.

Here’s another snag – heritable traits and inherited traits are not synonymous. To inherit something means you received it or get from your parents. Think about an heirloom. Your grandfather has this amazing fishing pole. When he passes on, he gives the fishing pole to your father and your father gives it to you. You get the exact same thing your father and grandfather had. Genetic inheritance works the same way. One parent has a gene or allele and he or she gives to you.

Heritability is the likelihood of getting something…in other words, you might get it. It’s not automatic – like genetic inheritance, but the chances look good.

Here’s an example: Autism: highly heritable but not inherited
Arthur L Beaudet of Baylor University examined genetic causes of Autism. He found specific gene disorders that can result in autism de novo, automatically or off the top. These disorders include an alteration of the genome causing complete loss of copy, gain of copy or disruption of a dosage-sensitive gene.

But research by Sebat et al. indicates that other genomic deletions and duplications may point to genes in which mutations may lead to autism, but doesn’t automatically cause autism. In other words, having these genes doesn’t mean you will automatically have autism, but your chances are high.

Thinking about human behavior and habits, many of us confuse genetic and cultural heritability, especially when comparing family members to one another. If it’s something positive like – good looks or being smart, then it is thought to be an asset. You feel like you’ve got the deck stacked in your favor. "Natural with no extensions. She get it from her mama."

But all too often we hear people say unpleasant and hurtful things and characterize failure as a family curse. For example, making bad grades or getting into trouble. “You get that bad behavior from your father”. The good news is that these behaviors are NOT genetic, not ingrained in that person. The similarity is coincidental or because of a habit. Habits can be changed. Genes cannot.