My interest in the science of attractiveness and attraction is nothing new. I’ve written about it in these pages and in a bestselling book. Understanding attractiveness is critical to our vocation as aesthetic physicians. Recently, I have begun to consider the role that epigenetics may play in attraction.
Epigenetics explains how behaviors secondary to environmental influences can be passed on to future generations. Lamarck infamously described the concept of heritable acquired characteristic behaviors based on recent lineage experiences. That was 150 years ago; he was disgraced and his theories were dismissed as potentially dangerous junk science. But epigenetic modifications that can be acquired in one generation and passed on to subsequent generations provide an explanation for some of the curious findings that led Lamarck to surmise we are a product of our recent environments as well as eons of evolution.
Epigenetic thinking casts aside the dichotomous “nature vs nurture” argument, yielding a gray mosaic. Epigenetics posits that something above or beyond the gene controls the output and fate of the determinate cell. And it is heritable. As one scholar puts it, “It is now clear that experiences, be it environmental toxins, maternal behavior, psychological or physical stress, learning, drug exposure, or psychotrauma, leads to active regulation of the…DNA.” (Neuron 80(3):1-17)
Peer reviewed research shows that epigenetic changes influence mate selection and possibly evolution. Female pregnant rats who have been exposed to a fungicide sire male pups with lower sperm counts and increased risk for other health issues that can persist for up to four generations. Females learn to sense the afflicted males and their offspring—and this learned behavior can pass on for three generations. Researchers speculate that this epigenetic change may work by “altering the MHC complex.” (PNAS 104(14): 5942–5946)
In another study, when male rats experience an electric shock paired with exposure to a specific odorant, their offspring display sensitivity to that odorant for up to three generations. (Nature Neuroscience.17:89–96)
Wow! This would be akin to you being afraid of dogs and unable to explain it until you later learn that your grandfather was bitten by a dog. Recent research has shown that epigenetic effects are evident in humans as well!
Is it possible that mate preference and selection in human beings might be influenced by epigenetic alterations? In animals, this has been demonstrated to occur via the all-important mate discerning major histocompatibility complex (MHC) protein complex.
The scientist in me recognizes that even if epigenetic changes increase our affinity for another, the influence would likely be minimal. Epigenetic methylations are reversible, and environments are dynamic, as are personalities, emotions, and the social zeitgeist of the time. But the romantic in me can’t shake the notion that science helps explain how our personal and ancestral history can guide us toward an ideal mate.