Although there are noticeable similarities between members in the same family among the majority of families, there are those that do have members who do not look like they are related. We have all seen the siblings where one is the ‘pretty sister’.

Even though these family members may appear to not have family traits, aside from being an adopted child or children from different marriages, they do have family traits passed to them, contrary to Mendelian Genetics, which are dominant in them, but not in other family members.

I am an example of such. Although I have similar facial features and build to family members, along our bloodline is a Cherokee heritage and I have a darker skin tone than anybody else in my otherwise pasty white family. What was not a dominant family trait became dominant in me. I often get asked if I am of Spanish, Greek, or Middle Eastern origin.

That’s scary! I hope they plateau at some stage.

“having photographed thousands of family group”

Wow, did you get some that just didn’t seem like a family at all i.e. all different shapes and sizes?

Although this does suggest a social conditioning (you eat as much or as little as the rest of your family eats), it does not rule out genetic dispositions toward either end of the weight scale.

Though there is a median of metabolism for the human body (male and female)there are variances and extremes of metabolism. Two people eating the same amount of food can vary by their weight based on their metabolism.

That being said, social conditioning still plays a factor in one’s weight, as one does not eat 3 full course meals at a single sitting based on their metabolism. Neither does one starve themselves based on their metabolism.

Interestingly, to look at a family of a particular body type would seem to suggest social conditioning at play, but physiological traits could be equally if not more responsible.

“If people around you are very thin then you will feel out of place and a need to slim down I guess?”

I have noticed that thin people tend to hang out with thin people and vice-versa. I am certain that overweight individuals feel out of place when they are the obvious minority… whether or not that is a motivating factor in losing weight is hard to say. My best friends have all been overweight, and associating with me doesn’t seem to make much of a difference for them. They continue to gain weight every year.