Maybe It’s (Not) Maybelline
In the early 19th century, it was generally accepted as fact that facial features predicted personality, and biographies of the day would include long descriptions of facial features. This “science” declined in favor with the discrediting of phrenology and the advent of photography. A recent experiment suggests a hormonal link between appealing personality traits and particular facial features.
[W]hat would really help is a breeding experiment which allowed the shapes of faces to be followed across the generations to see how those shapes relate to variations in things that might be desirable in a mate. These might include fertility, fecundity, social status, present health, and likely resistance to future infection and infestation. Correlations between many of these phenomena and attributes of the body-beautiful have, indeed, been established. But in a pair-forming, highly social species such as Homo sapiens, you also have to live with your co-child-raiser or, at least, collaborate with him or her. So other things may be important in a mate, too, such as an even temper and a friendly outlook.
The story starts in 1959, in Novosibirsk, Russia. That was when Dmitry Belyaev, a geneticist, began an experiment which continues to this day. He tried to breed silver foxes (a melanic colour variant, beloved of furriers, of the familiar red fox) to make them tamer and thus easier for farmers to handle. He found he could, but the process also had other effects: the animals’ coats developed patches of color; their ears became floppy; their skulls became rounded and foreshortened; their faces flattened; their noses got stubbier; and their jaws shortened, thus crowding their teeth. All told, then, these animals became, to wild foxes, the equivalent of what dogs are to wild wolves. And this was solely the result of selection for what Belyaev called “friendly” behavior — neither fearful nor aggressive, but calm and eager to interact with people.
The link appears to be hormonal. Hormones such as estradiol and neurotransmitters such as serotonin, which regulate behavior, also regulate some aspects of development. Change one and you will change the other. So in a species where friendliness is favored because that species is social and the group members have to get on with each other — a species like Homo sapiens, for example — a “friendly” face is a feature that might actively be sought, both in mates and in children, because it is a marker of desirable social attitudes. And there is abundant evidence, reviewed by Dr. Elia, both that it is indeed actively actively sought by Homo sapiens, and that it is such a reliable marker.