To be fair, I don’t look like my brother, or share any mannerisms with him, but we have really similar world-outlooks. I’m religiously observant, but I waffle from day to day on whether I actually believe in HaShem. He is proudly Atheist, but owns up to being ethnically (or as he puts it “culturally”) Jewish just to keep our numbers up.
His wife is an Atheist who was raised Korean Methodist. They celebrate Chrismukkah. And occasionally Fetivus.
My parents had very different temperaments, and I think managed to live together because they were so well-aligned with their opinions. My father died almost 20 years ago, and my mother’s second husband is a lot like her in temperament, but opposite in opinions.
It may depend on how much parents agree. If you have parents with wildly divergent attitudes toward something, a child, rather than taking after one or the other, could be like those children who have one blond parent and one brunette parent, and end up with red hair.