Heredity influences body weight, but there is no single “obesity gene”. More likely some genes influence how quickly the stomach tells the brain “I’m full”
Molecular behavior genetics is to find some of the many genes that together orchestrate traits such as body weight, sexual orientation, and extraversions
If all schools were of uniform quality, all families equally loving, and all neighborhoods equally healthy, then heritability would increase (because differences due to environment would decrease)
Go barefoot for a summer and you will develop toughened, calloused feet, a biological adaption to friction meanwhile your neighbor will remain a tender foot.