I don't think human DNA generally codes for the behavior derectly. Rather, DNA can code for how the brain learns from incoming data streams.

If the brain naturally tunes into some sources or patterns of input rather than others, it may learn very quickly from the preferred sources. And as long as those sources carry signals that are fairly invariant over time, it may seem like those signals are instinctual.

For instance, it may appear that humans learn to build relationships with kin (both parents and children) and friends, to build revenue streams (or gather food in more primitive societies) and reproduce.

Instead, the brain may come preloaded to generate brain chemicals when detecting certain stimuli. Like oxytocin near caregivers (as children) or small fluffy things (as adults). When exposed to parents/babies, this triggers. But it can also trigger around toys, pets, adopted children, etc.

Friendship-seeking can be, in part, related to seretonin-production in certain social situations. But may be hijacked by social media.

Revenue-seeking behavior can come from dopamin-stimulus from certain goal-optimzing situations. But may also be triggered by video games.

And the best known part: Reproductive behavior may primarily come from sexual arousal, and hijacked by porn or birth control.

Each of the above may be coded by a limited number of bytes of DNA, and it's really the learning algorithm combined with the data stream of natural environments that causes specific behaviors.

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ACCount37 16 hours ago | parent [-]

A lot of animals are born "hardcoded" with most of the instincts they need to survive, so some behaviors are clearly innate.

And "how the brain learns from the incoming data streams" is, in part, driven a set of behaviors too.

A baby's eyes are trying to detect and track certain preset features long before the primary visual cortex learns to make sense of them. That's a behavior, and it exists for a reason. As the baby develops, the baby would try to seek out certain experiences to learn from them, which is a behavior that exists for a reason too.

There's a hypothesis that certain mental disorders are caused by this innate learning process going off course, but it's just a hypothesis, of the kind that's hard to prove conclusively.

	▲	trashtester 2 hours ago \| parent [-]
		Indeed. But most instincts involve elements of learning. Meaning the instincts may be stored using a much smaller number of bits than if they were stored as traditional IF-THEN-ELSE computer program. For instance, the pattern the brain seeks to optimize to learn to work may be much smaller than the full algorithm for walking. And if the brain learns quickly enough (and if a newborn animal started learning elements such as balance, moving legs, etc, before even being born), learning to walk may be learned in minutes instead of months.