Inherited Personality Traits?

My son has had his new car only for two weeks now, but he's washed it at least half a dozen times. He went to Wal Mart, and bought all sorts of specialized paraphernalia meant to maximize car washing effectiveness, including a chamois, a big, fuzzy glove, some thing that looked like blue Medusa hair, and several other things.

Seeing all of this stuff, combined with the frequent car washing reminded me strongly of my brother. When my brother was about my son's age, he had a Porsche 911S that he washed almost every day with a similar variety of car washing paraphernalia. I can remember our mother teasing him, telling him that he'd wash all the paint off the car if he kept washing it so often.

Besides this, my son displays a lot of my brother's ways. Neither of them are overly tidy when it comes to general housecleaning habits, but when it comes to their personal belongings, both are meticulous. Both are fussy about how their electronic equipment is handled; I can remember my brother lecturing me about the proper way to handle an LP record and now I see my son being similarly careful with his CDs and DVDs.

Both are creative, musically and artistically. I share the musical talent with them, but I have no talents whatsoever for the visual arts. They are both rather private people, not backslapping, "one of the guys" types. They tend to take an avoidant approach to conflict -- most of the time.

But the thing is, my son doesn't know my brother, really. They've met a handful of times in my son's life and have never spent any extended length of time together. He most definitely hasn't picked up my brother's ways from observation.

We all know that physical traits are inherited. Is it possible that personality traits are in the genes as well?

Thoughts?