I can grasp the concept that our genes direct how organisms develop the various organs and body parts, but how are things like how birds know how to create intricate nests, bees know how to do their little dances to show where to find flowers, and other apparently un-learned, instinctive behaviors passed on? Are the neurons in the brain pre-wired by the genes?
Yes, that’s exactly it. The brain evolves through natural selection to have certain behaviors ready to go. Humans have lots of instincts, too, but are also better at learning. Bees are probably mostly hardwired.
Yes, but you have to be a little careful with the choice of vocabulary “pre-wired”. Genes mean nothing without environment. When we talk about something being (to some degree) innate, what we mean is that given a specified environment, a difference in genes leads to a difference in behavior. This does not imply that the environmental conditions are unimportant in building the brain, or that a change in environment might not also lead to a change in behavior.
As to just how a difference in DNA leads to a difference in neuron configuration and thus a difference in behavioral phenotype? We know very little, aside from simple examples in model animals.
Here’s a good, short non-technical article.
The effects of genetic variation on other cognitive and behavioural traits are similarly indirect and emergent. They are also, typically, not very specific. The vast majority of the genes that direct the processes of neural development are multitaskers: they are involved in diverse cellular processes in many different brain regions. In addition, because cellular systems are all highly interdependent, any given cellular process will also be affected indirectly by genetic variation affecting many other proteins with diverse functions. The effects of any individual genetic variant are thus rarely restricted to just one part of the brain or one cognitive function or one psychological trait.
What all this means is that we should not expect the discovery of genetic variants affecting a given psychological trait to directly highlight the hypothetical molecular underpinnings of the affected cognitive functions. In fact, it is an error to think of cognitive functions or mental states as having molecular underpinnings – they have neural underpinnings.
The relationship between our genotypes and our psychological traits, while substantial, is highly indirect and emergent. It involves the interplay of the effects of thousands of genetic variants, realised through the complex processes of development, ultimately giving rise to variation in many parameters of brain structure and function, which, collectively, impinge on the high-level cognitive and behavioural functions that underpin individual differences in our psychology.
Heck, we have a hard enough time understanding how genes lead to purely physical things like “arms on top, legs on bottom”.
Beavers have an inherent sense of unease caused by the sound of running water and an urge to pile things on top of the source of the sound, using sticks if they are available. There have been experiments done with young beavers and speakers sitting on the concrete of their cage. No moving water, just the sound.
So, what are human instincts?
I would imagine it includes suckling. Is the drive to fornicate considered an instinct? What are others?
There is a stepping instinct https://www.healthline.com/health/baby/stepping-reflex
I don’t know what to make of this question. Everything we do is informed by innate tendencies. We have the instinct to acquire language, the instinct to be social and cooperative, the instinct to be aggressive, the instinct to be kind, you could describe hundreds of innate tendencies - but there is no list of discrete behaviors, and few things are governed solely by instinct.
When a layman like myself thinks of instinct, it is used to describe behavior that hasn’t been learned. I think the OP would agree, as he mentioned instinctual behavior.
If a beaver is building a dam, he’s not doing so because he learned it from another beaver. Same with a bird building a nest. You could isolate a bird from other birds and it would build a nest if it could. It’s instinctual.
So if you isolated a human, what behaviors would he engage in, that he hasn’t had to learn from other people?
I can see how walking is instinctual. A person will develop the skill to walk without needing to be taught.
I was trying to analogize human behaviors to the things mentioned by the OP, like bee dancing and nest building. I get your explanation, but I was wondering if there were more discernible actions than just things like “be kind”.
ETA: Hasn’t it been said that humans have instincts for “feeding, fleeing, fighting, and fucking”?
I’m not sure why you are highlighting the word behavior as though I’m talking about something else. Everything we do is behavior.
But we are so much more complex. In humans the few discrete simple behaviors that are purely instinctual (like suckling) are such a minor part of who we are. The entire structure of our brain, our personality, every thought we have and everything we do, it all derives from a complex interplay of innate and environmental factors.
I never meant to suggest otherwise.
Instead, I was curious about examples of these “discrete simple behaviors”, as it’s fascinating to think about things I may do that are purely instinctual, precisely because human behavior is so complex.
I think part of the problem is that we have through evolution replaced a lot of instinct (“innate behaviours”? “Programming”?) with monkey-see-monkey-do learning. We can either consider some instincts atrophied or replaced; it’s probabaly the same to an extent in most higher mammals, but we are the apex of that process. Our brain is “wired” to observe a solution ot a problem, or optimal-result behaviour, and copy it; if necessary, embellish it.
You could argue that some behaviours, like the physical act of sex, are “instinctive”. OTOH, over time, thanks to the internet, that instinct may atrophy too and be replaced by observational learning.
But seriously… I would argue there are some things which might qualify. Many people have a visceral reaction to, for example, snakes. Why are gerbils or puppies cuddly, but not rats - is that learned or instinctive? Assorted psychology tests show that certain female characteristics strongly appeal to mature males - hard wired, but can sometimes be overridden by some learned behaviour.
An aside, if you’ve ever seen real beaver country, it’s trying hard to convince you there is a higher purpose directing evolution. They dam up the creeks meandering through the forest, creating ponds that eventually silt up - and so the beavers move on to the next one… Those silted-up ponds cover the bare rock, become lush meadows encouraging the growth of thicker undergrowth and then forest. Mother Nature is atoning for having scraped the pre-Cambrian Canadian Shield bare of topsoil 20,000 years ago.
Throwing projectiles, which might even include spitting involves some very complicated computations seems to be a combination of instinct and practice. Another one is faking discomfort for sympathy. I have seen very small babies do this. I guess it would go along with a manipulation instinct.
I agree on the throwing part – little kids are really good at throwing stuff, and terrible at catching stuff. Dogs, on the other hand, are great at catching things. It really seems to be an instinctual difference.
There is pretty clear evidence that humans have an instinct for language.
There’s also some kind of fairness instinct that we share with other primates. Some monkeys will refuse a treat if they think another monkey is getting a better treat. Humans will react really strongly to a line cutter or a perceived slight on the road (to the point of murder!), even though the actual difference in time spent in line or in traffic will be a minute or something.
Infants up to six months old have an innate ability to swim and dive, holding their breath and lowering heart rate to conserve oxygen and warmth. It’s considered a primitive reflex because it fades away as one ages. I’d consider than an instinct, even if only a temporary one.
This is a very strange idea. We are the product of natural selection. You are basically arguing that at some point natural selection turned our brains into blank slates at birth, where nothing about our cognitive structure is determined by natural selection. It is highly implausible that this could ever have been adaptive, that a person born as a blank slate would have been fitter than a person with a brain shaped by innate determinants.
Instinct has not been “replaced”, innate factors still influence everything about our cognition, just as with any other animal. What is different about us is that there is a huge amount going on in addition to this - cultural transmission, a much more sophisticated ability to use higher cognition to reason and to adapt to the environment. We integrate a large number of (potentially conflicting) instinctive tendencies and learned/reasoned objectives and ideals into optimal decisions.
A fellow student back in the day told me that one of the professors got a little upset when he referred to the psychology department as “the place where they torture rats”. I recall a Scientific American article long ago, where the psychologists expanded their repertoire to kittens, puppies and young babies.
They had a box marked in black and white checker squares about a foot on a side. One half, the floor dropped off about 4 feet and there was a glass floor extending the higher side. Because of the check pattern, the drop was obvious. They’d put a youngster in there, and no surprise - puppies, kittens, or babies learning to crawl - they stayed away from the glass floor because it looked like a four foot drop. I hope that among the sample of babies, not all of them had fallen off a sofa or out of a crib in their experience. So like the puppies and kittens, they had an “instinctive” ability to understand the shape of their novel surroundings, based on paint patterns, and an instinctive understanding “gravity - bad!”. I suppose that jumping off a bridge is something you learn from your friends as you get older.
What I am suggesting is that human instinct is not as strong as in some animals, because learning from elders has replaced a lot of the behaviour that in less brainy animals is innate and instinctive. It’s evolutionary logical - for example, fear of fire is far less in humans than in, say, assorted forest creatures. (Or bees - “smoking” bees creates an instinctive reaction where they tend to ignore intruders to focus on loading up on honey in case they need to swarm… handy for beekeepers) Our learned expereinces are better than the basic instinctive ones. We don’t need to know how to build shelters or cook food or make tools innately, we figure it out, especially if we just copy what grandpa did.
There’s the bit on some memoirs where on one of the earliest British ships to visit the Galapagos, a sailor was pouring a cup of water from a pitcher. As he did, a bird landed on his arm to drink from the stream of fresh water. After people had lived on the island for twenty years or so, a visitor reported a young boy sitting by a watering hole with a stick. The birds would not come within a yard of him, but he could still quickly hit some - easy hunting. There was some sort of “skittishness” switch in the birds, which by process of elimination (so to speak) was slowly becoming dominant.
We still have plenty of instincts. We are social animals, and the need for companionship, for peer approval, for social dominance, the urge to pair up and reproduce, are all deeply ingrained instincts. (But again, with sexual behaviour, the learning mind can override these instincts in some instances)
In the sense that any given human behavior integrates instinct with learning and reason, sure. But I think it’s much more correct to say that learning and reason are added inputs in a much more sophisticated cognitive architectue, they have not replaced instinct.
And this language still to me belies the flawed model in many of the posts here that a specific behavior is an instinct. In a few trivial cases like suckling, sure. But the vast majority of our behavior integrates instinctive tendencies with learning and reason.
Not that you have suggested it, but it’s also a very common and deeply flawed model that we have “base” instincts and that reason allows us to “rise above them”. But it’s complete nonsense - our social cooperative behavior is just as much a part of our nature as fighting and fucking.