Spending time on outsider activities makes it much easier to leave your tribe. In that sense, people who do so really are less trustworthy, because they have options other than helping out when things get tough. People who value loyalty are going to want to be around people who aren't trying to build the ability to leave them. So, if you want to be around a person who values loyalty, signalling that they are the best match for your skills and knowledge is helpful.
I do think there must be some aspect of that in the situation but I don't think that is complete.
Seems that trust here is also connected to loyalty -- we're all in the same ship and will suffer the same fate. Those who have options elsewhere do have more choices but that itself doesn't imply they are less trustworthy or loyal to the group. (Though I agree some will cast them in that light.)
If things get tough what should the group action be? Just keep doing as before and suffer; even if that means the ultimate demise of the group? Maybe. Or perhaps the approach would be more like over time things change and the group also needs to evolve. Those with outside exposure, who have clearly signaled a commitment to the group by staying when they could have changes associations already, might be the very members that can help save the group while preserving the "essence" of the group. (There's probably a very large post (collection of posts) needed there ;-)
So who should members trust here and why? Seems like this is just a bit of a microcosm of what we see in lots of social and politic behaviors in the world at larger levels (which I assume the point of the OP might have been).
For those who have not heard of it, the book Exit, Voice and Loyalty, by Albert Hirshmann, might be a worthwhile read.
Well, it seems like it's still the case in situations where people can't (or won't) leave their tribes. For example, men and women aren't usually each other's outgroup and in situations where no one plans or gives indication of "leaving" a gender, it's still bad for say men who have all intentions of remaining men to signal too much knowledge of girly movies, chick flicks etc.. But that works in the other cases I brought up -- the local citizen who is too into foreign stuff might pack up and leave, or a nerd/jock/artsy person who is too into the other clique's stuff might also switch peer groups.
I feel like things in some cases may be driven by "neutral" outsider stuff competing for attention/time/cost from "good" ingroup stuff, even in situations where you don't leave your ingroup, so maybe it's "bad" in a non-zero sum way even in situations where you don't see the outsider stuff as bad in absolute terms (i.e., why don't you spend more effort on ingroup stuff, which would be "even better", even if I'm not opposed to outsider stuff?).
Here's another example that often makes me laugh: The employees of my local organic grocery store have this habit of signaling strongly to each other how little they know about handling the shop's technical devices.
With all the truth-seeking that goes around here it's easy to forget that knowledge is not the ultimate value agreed upon by everyone and used as foundation for every other value. Not even close, and for good reasons.
Knowledge is not the goal behind most things we do. Yes, studying and research happen. Lots of other, not knowledge-focused activities happen aswell.
Knowledge is the byproduct of practically any activity. Whatever you do, it's hard to avoid gaining some knowledge in the process. And that is precisely why "I'll have more knowledge" is not a good argument to justify any activity. Picture the worst immoral action you can think of. If you perform it, you will be more knowledgeable about the world (probably in more ways that you can currently imagine).
But, reversed familiarity with outgroup stuff isn't familarity with ingroup stuff, or vice versa, similar to how reversed stupidity is not intelligence (https://www.lesswrong.com/posts/qNZM3EGoE5ZeMdCRt/reversed-stupidity-is-not-intelligence).
"Reversed stupidity is not intelligence" is an idea that needed to be stated because it is counter-intuitive. We naturally tend to look for 2 matching opposite ideas that can be mapped onto "good-bad" intensity scale. Pick any pair of antonyms for simple example, or any pair of virtues and sins for example more relevant to this particular discussion. Because whatever is associated with an outgroup feels like sin and whatever is associated with ingroup feels like virtue.
It's mainly about associations.
The outgroup is bad. There are beliefs and behaviors associated with the outgroup.
Therefore these beliefs and behaviors are bad. If I show any of these beliefs and behaviors people might think I'm bad.
Yes this is flawed logic, but it's not something people think about logically in the first place. That's just how we normally feel.
And it's important to remember that there can be consequences for signalling or lack of signalling.
And people tend to care about these consequences way more than they care about abstract knowledge.
But of course your examples of it being harmful are valid
Some examples are cases where people in groups renowned for or labelled for some trait (e.g., jocks, supermodels) are stereotyped as "unintellectual" as part of their identity and thus hide or cut off their intellectual interests.
The opposite is also true, I've known some people who seriously neglected their health because they associated exercise with not-so-bright folks. Notice how it has the same process behind it, but it's not related to knowledge the same way your example was. And I do agree that this is not a good basis for decision-making.
It's just it's not always quite as simple as in these examples.
Maybe not. Maybe some people can transcend all the arbitrary norms, and avoid forming their own arbitrary norms, and find a way to interact with everyone else without signalling, and not end up practically exiled, but I'm not hopeful.
It's something fairly difficult to do in practice and I'm yet to see examples of people succeeding at it long term.
It's mainly about associations.
The outgroup is bad. There are beliefs and behaviors associated with the outgroup.
Therefore these beliefs and behaviors are bad. If I show any of these beliefs and behaviors people might think I'm bad.
Fair, but I mentioned examples where the (not necessarily outgroup in an rivalrous way but non-ingroup) outsiders are not seen as bad per se, but neutral whereas the ingroup is good.
For instance a local citizen might not be seen as "bad" for being interested in foreign stuff (if the foreign countries in question are not seen as bad, just "other", or possibly fargroup, or even viewed positively just "not us"), but this would still take away from perception of patriotism (here, assumed as positive trait) that a similar local citizen who all else being equal totally lacks interest or curiousity in foreign stuff.
Also, men and women aren't each other's outgroups usually (barring some more radical views) but a man who in too interested into "girl stuff" or vice versa can be seen as bad even in situations where there is no confusion where the ingroup can't be confused with the other group. I suppose the "outgroup stuff is bad" still works if you define "bad" relative to the person's social role. Such as "girl stuff" is "good" for girls", "bad for boys", even if boys and girls are equally good. "French stuff is good for French people but bad for British people", even if British and French folks are equally good.
Then it's about transgression of roles I guess and policing which stuff are for what people.
The opposite is also true, I've known some people who seriously neglected their health because they associated exercise with not-so-bright folks. Notice how it has the same process behind it, but it's not related to knowledge the same way your example was.
I would agree that that reversed example of the nerd and jock is also bad, and perhaps could generalize that to avoid learning skills/abilities/things, instead of just intellectual knowledge, that would benefit you because it's associated with the other outgroup/non-ingroup members.
I guess when there is a scale from X to Y, you can make yourself appear to be more X by conspicuously avoiding everything associated with Y. In context of ideological groups it means "more loyal", in context of gender it means "more masculine/feminine"; in both cases it is "more <what defines this group>".
But why not do more X instead? Maybe there are diminishing returns to signaling X. (Killing a bear with your hands makes you masculine, but does killing two bears with your hands make you twice as masculine?) Or maybe complete scope insensitivity (two bears, twenty bears, it's the same thing -- you either are a "bear-killer" or not). Not sure about this part.
I used to work with some techies who would signal their lack of knowledge of sport by using phrases such as "cricket racket" , "tennis bat" and "football tournament"
Here's a phenomenon I was thinking about.
In many situations, knowledgeable people don't just go out of their way to show off how much they're familiar with things that raise their clout with the ingroup -- for example, an artsy person rattling off names of obscure artists to his artsy friends, or a very patriotic person singing her country's historic folk songs or preparing its national foods.
It's also the case that many will go out of their way to deny or signal lack of knowledge about things that are either associated with outsiders or non-ingroup, if not necessarily outgroup, members.
For instance, a patriotic person bragging about how little he knows about foreign customs, foods, or languages that are not well-known in his own country. Or a proudly nerdy or "indie" kid claiming to not watch a popular TV show, and bragging she knows nothing about the local sports team or latest celebrity gossip, in contrast to her narrower ingroup's own niche interests.
What I find interesting is this:
There seems to be a social "penalty" of sorts in many groups for knowing too much outsider stuff, regardless of if it really comes at the expense of insider stuff.
Imagine you have some people.
Person A: Is very knowledgeable about ingroup stuff. Knows very little about outsider stuff.
Person B: Is as equally knowledgeable as person A on ingroup stuff but on top of that also knows a lot of outsider stuff. So, knowing what A knows and then something else.
Person C: Is more knowledgeable than person A and B about ingroup stuff AND outside stuff alike. So is more knowledgeable than A and B across the board.
It's interesting that people will sometimes see person A as higher status, more proud, loyal, patriotic or whatever, towards the ingroup, than person B or C, even if the latter two have already what A has in terms of ingroup stuff or even added more. In fact, person B or C may be labelled even less like-one-of-our-ingroup than say, another less knowledgeable across-the-board person D, who knows even less than A, B or C about either ingroup or non-ingroup stuff, but happens to know just-a-little-bit of ingroup stuff but no outgroup stuff. Maybe in some scenarios, it's the ratio of familarity with ingroup stuff than non-ingroup or outgroup stuff that matters, not absolute familiarity with ingroup stuff.
There could be a number of causes for this I imagine, even setting aside the very adversarial cases that knowledge, familiarity, or interest in outsider stuff may signal you may want to help an outgroup with vested interests to harm your ingroup (such as showing interest in learning the foreign language or customs of an adversary in a political conflict such as war). Maybe people perceive ingroup and non-ingroup stuff as competing or zero sum in time, effort or cost and thus not spending more time on ingroup stuff is seen as disloyal even if the outgroup stuff isn't seen as bad per se (e.g. why are you less patriotic for spending or showing interest travelling and learning about foreign places, even after you've travelled locally enough? You could be spending even more time and effort on local stuff, maybe.).
People constantly drop, hide or otherwise pretend to lack knowledge or skill with outsider stuff to try and fit into ingroups, even though it's not like dropping the extra non-ingroup knowledge adds to their ingroup knowledge.
But, reversed familiarity with outgroup stuff isn't familarity with ingroup stuff, or vice versa, similar to how reversed stupidity is not intelligence (https://www.lesswrong.com/posts/qNZM3EGoE5ZeMdCRt/reversed-stupidity-is-not-intelligence).
Should we treat this state-of-affairs as a good thing? For those who value pursuit of knowledge, skill and openness for its own sake (if it's not harmful to others at least), there's a lot of wasted potential (and squandered opportunity for self-actualization) in people not pursuing their full goals because learning new things is bad for ingroup identity.
Some examples are cases where people in groups renowned for or labelled for some trait (e.g., jocks, supermodels) are stereotyped as "unintellectual" as part of their identity and thus hide or cut off their intellectual interests. Having a PhD in astrophysics, or joining a very academic book club to read about medieval French history doesn't make the strong person weaker or the supermodel less physically attractive but it's possibly associated with people like effete intellectuals or unseemly dorks who are not in the athlete or beauty queen's ingroup.
Children of culturally-distinctive immigrants (or ethnocultural minorities that are distinctively non-mainstream in culture) can feel pressure to drop knowledge or familiarity with minority-culture stuff to be seen as more assimilated than someone who's never jettisoned minority-culture stuff at all, but just added enough mainstream-culture-stuff to match the other mainstream-culture members.
Men can refrain from honing or pursuing their skill in feminine hobbies or activities, or women in masculine ones, even if they already have excellent skills in more gender-conventional ones, and the newer ones would not detract or be in opposition to them. And there are many more examples like this.