Can behavior be inherited?

When my son was 3 months to 9 months his father was deployed and yet there were expressions and reactions that were extremely similar to his dad. He was only with his dad for the first 3 months.

Over the years he has taken on other similarities but I figure those are from nurture. But in his early months his hand gestures and facial expressions where spot on to his fathers. Now he has changed and is a mix of several people in behavior and expression. One being my brother. There are things that remind me so much of my brother and the way he views the world. So much so that for many years I would say my brothers name when calling my son and vise versa. Just so you know. My brother only lived with us for a short while for a total of 10 months on and off when my son was young, and when he didn’t live with us he lived states away.

Can an infant of 3 months or less pick up these gestures from watching or is it genetic and one of natures ways to get father and son to bond?