The most obvious behaviour is sometimes the least noticed. I couldn’t tell you how many times I went to the bathroom today, nor where or when I felt hungry. All of those mechanical scripts occur at a level underneath consciousness.
In bigger ways, too, we have patterns. For instance, in our search for the ideal coupling mate, the drive to find someone else out there keeps us scanning the horizon. We’re like cheetah on the veldt, lounging in a tree, looking for the right shape or movement to signal lunch. Only the lunch we’re after is potentially the most important person in our lives.
Tricky, this, because checking at the horizon necessarily precludes looking closer to home. This element of otherness, of finding the exotic, is a well-defined human characteristic. Yes, we look for some markers of similarity, but being complementary (and metaphysically far away) is an input to our choice.
The two extremes of this are arranged marriages, and marriages of people from completely different cultures, ethnicities and geographies. They are the same institution, but we innately feel that the non-arranged union is more likely to succeed; we are strongly predisposed to this idea.
Which of course makes sense when we think about it from a biological point of view. Reproduction via sex works best with diversity. Get too many closely-related folks having babies and the system fails to operate, shall we say, optimally.
But if you stipulate that in a large city, for example, the genetic diversity is sufficient, the cultural attractions (of an individual) become more important. Some things the same, some things different, some things we love, some things we despise; this is the recipe for finding someone.
Perfection it is not. But if we wait for perfection we’ll wait forever.