In particular, costly signalling must be negative-value for an individual
That’s one way to do things, but I don’t think it’s necessary. A group which requires (for continued membership) members to exercise, for instance, imposes a cost, but arguably one that should not be (necessarily*) negative-value for the individuals.
If it’s not negative value, it’s not costly signalling. Groups may very well expect members to do positive-value things, and they do—Mormons are expected to follow strict health guidelines, to the extent that Mormons can recognize other Mormons based on the health of their skin; Jews partake in the Sabbath, which has personal mental benefits. But even though these may seem to be costly sacrifices at first glance, they cannot be considered to be costly signals, since they provide positive value
If a group has standard which provide value, then while it isn’t a ‘costly signal’ it sorts out people who aren’t willing to invest effort.*
Just because your organization wants to be strong and get things done, doesn’t mean it has to spread like cancer*/cocaine**.
And something that provides ‘positive value’ is still a cost. Living under a flat 40% income tax by one government has the same effect as living under 40 governments which each have a flat 1% income tax. You don’t have to go straight to ‘members of this group must smoke’. (In a different time and place, ‘members of this group must not smoke’ might have been regarded as an enormous cost, and worked as such!)
*bigger isn’t necessarily better if you’re sacrificing quality for quantity
**This might mean that strong and healthy people avoid your group.
That’s one way to do things, but I don’t think it’s necessary. A group which requires (for continued membership) members to exercise, for instance, imposes a cost, but arguably one that should not be (necessarily*) negative-value for the individuals.
*Exercise isn’t supposed to destroy your body.
If it’s not negative value, it’s not costly signalling. Groups may very well expect members to do positive-value things, and they do—Mormons are expected to follow strict health guidelines, to the extent that Mormons can recognize other Mormons based on the health of their skin; Jews partake in the Sabbath, which has personal mental benefits. But even though these may seem to be costly sacrifices at first glance, they cannot be considered to be costly signals, since they provide positive value
If a group has standard which provide value, then while it isn’t a ‘costly signal’ it sorts out people who aren’t willing to invest effort.*
Just because your organization wants to be strong and get things done, doesn’t mean it has to spread like cancer*/cocaine**.
And something that provides ‘positive value’ is still a cost. Living under a flat 40% income tax by one government has the same effect as living under 40 governments which each have a flat 1% income tax. You don’t have to go straight to ‘members of this group must smoke’. (In a different time and place, ‘members of this group must not smoke’ might have been regarded as an enormous cost, and worked as such!)
*bigger isn’t necessarily better if you’re sacrificing quality for quantity
**This might mean that strong and healthy people avoid your group.