I don’t think the science is out on that. For instance, your capacity to fall in love with someone is influenced by their smell as it contains information about their immune system (and, by extent, their immunological compatibility with yours).

Most humans have a need for companionship. It’s the reason solitary confinement is considered torture in most cases. Our brains and bodies are rigged to prefer companionship over being alone most of the time. Put a human alone in a room with a plastic ball with a face drawn on it for long enough, and that plastic ball will be given a name, a personality, and that human will get upset if you dare “hurt” the plastic ball. In a much more dystopian twist on that experiment, people have started “befriending” LLMs now that they’ve grown to have the ability to remember a couple hundred keywords about your user account. The human mind craves being around others.

However, I don’t think whether you like someone or not is purely a function of what they provide for you. You can enjoy the presence of your friends even if you’re sitting in a room silently scrolling on your phone, or watching a TV show.

Their opinions and behaviour towards others definitely also matters. Shared experiences also factor into this stuff somewhere; someone you would normally detest who might’ve been with you through bad times/some traumatic event might end up becoming a friend. Years and years of positive experiences can also make you find excuses for things you would reject in others (which is why even the worst people can have their families and friends protect them). Your friends may have turned into terrible people over the years, and you will find ways to defend their behaviour to yourself and others just because they’re your friends. Similarly, someone you know well might do something terrible out of the blue, and you will recognise that as an outlier event (mental health crisis? sign of illness?) rather than distancing yourself from them like they’re some weirdo in the street.

Maybe ask yourself this: if your friends got hit by a car tomorrow, and suddenly lost their ability to hold an interesting conversation, make witty jokes, or play video games with you, would you stop caring about them? If not, then there’s clearly more to your relationship with them than the basic experiences they can provide.