If you search Google for the phrase “80 percent genetic”, you will discover hundreds of sources that claim that everything from schizophrenia, to height, to intelligence has been found to be four fifths ‘genetic’.

Imagine that we could study a population where everybody lived in an identical environment. They did the same things everyday; they ate identical foods, had identical relationships and were stressed by identical events.

A twin study would find that mental illness would be close to 100% heritable, because if the environment is fixed, any difference must be down to genetics.

if we only studied genetically identical clones, everything would be 0% heritable, because any difference must be down to the environment.

the process of measuring the influence of genetics is, itself, subject to environmental factors. It captures the dance, not the dancers.

we are not environment versus genes. We are their sum, their product and their expression. They dance together and we are their performance