Define Heritability: “Heritability is a measure of how well differences in people’s genes account for differences in their traits. Traits can include characteristics such as height, eye color, and intelligence, as well as disorders like schizophrenia and autism spectrum disorder.”
Define Environment: “The circumstances, objects, or conditions by which one is surrounded”
Define Trait: A trait is a specific characteristic of an organism. Traits can be determined by genes or the environment, or more commonly by interactions between them. The genetic contribution to a trait is called the genotype. The outward expression of the genotype is called the phenotype.
What is Heritability?
Heritability, in the simplest terms, is a measure from zero to one indicating to what degree people’s traits are biologically driven or a result of environmental factors. Specifically, heritability (measured as h2), estimates whether a variation in a specific trait is due to a variation in genetic factors in a given population as opposed to environmental factors.
A heritability estimate of zero indicates almost all the variability in a trait between people is due to environmental factors, with no consideration for genetics. Religion, language, and political preference all have a heritability of zero as a person’s genes have nothing to do with their preference and selection of these specific characteristics.
Conversely, traits with a heritability close to one indicate that the variability between people is a result of genetic factors and not the environment. Height has a heritability of approximately 0.8, meaning that ~80% of the variance between people is explained by genetic differences, with very little (5-10%) influence from environmental factors.
Many traits do not fall on one end of the spectrum or another. Complex traits like intelligence, or IQ, lie somewhere in the middle.
Heritability is not applied to an individual, but rather a population. A heritability estimate of 0.75 for weight does not mean that 75% of a person’s weight is determined by genetics and 25% from the environment. Rather, it means that 75% of the variation in a population’s weight is due to genetic factors, while 25% is due to environmental factors (diet, exercise, etc.). For readers, this is to say you often aren’t “stuck” with a trait even if there is influence from your genes. Powered by good information, you can take necessary steps to improve many traits, much like weight, muscle growth, sleep schedule, and much more.
Why do we at Pregenic care?
For scientists, heritability can serve as a starting point for analysis! Heritability tells scientists how genetics may play a role in specific traits, and points us where to study further. Social scientists also use heritability in their research, noting that traits like how many hours you sleep, when you sleep, and how much coffee you drink in the morning could be at least a little heritable.
At Pregenic, through DNA testing, we aim to help you make sense of your traits (along with many other factors) to help you be healthier, happier, and stronger. Our mission is to provide genetics-based individualized health risk guidance for everyone. By analyzing your DNA, our goal is to provide you with individualized health insights to improve your lifestyle and postpone the consequences of disease.