Toughness is a topic I spent some time thinking about today. The way I think about it is that toughness is one's ability to push through difficulty.
Imagine that Alice is able to sit in an ice bath for 6 minutes and Bob is only able to sit in the ice bath for 2 minutes. Is Alice tougher than Bob? Not necessarily. Maybe Alice takes lots of ice baths and the level of discomfort is only like a 4/10 for here whereas for Bob it's like an 8/10. I think when talking about toughness you want to avoid comparing apples to oranges.
I suspect that toughness depends on the context and isn't a completely general skill. Alice might be more physically tough than Bob, and Bob might be more socially tough, meaning that he's better at doing things like avoiding peer pressure. And maybe Alice is more morally tough, resisting the urge to lie and cheat. Maybe Bob is more cognitively tough; he's better able to able to deal with things like juggling lots of things competing for his attention. Maybe Alice is more emotionally tough and is better able to resist the urge to suppress difficult feelings instead of facing them.
All of this is pretty "back of the napkin". It's just kind of an initial attempt of me thinking about the topic. There's probably a better way to categorize things. And the categories I came up with probably have a fair amount of overlap.
I'm not sure how important toughness is. Physical toughness probably isn't very important in our modern world. I could see cognitive, emotional, social and moral toughness being pretty important. And rationality toughness! But then again, maybe not.
Consider social toughness. Suppose Alice has a hard time saying no to people. I see two broad ways of dealing with this:
I feel like (2) is usually more appropriate than (1) -- in this particular situation, in other "social toughness" situations, and in other "toughness" situations. It usually makes sense to make the thing easier than to improve your ability to push past it.
This is just a hunch though. I'm not sure. And I think that this "ability to push past it" thing is at least somewhat important.
You don't want to become too tough though. I think it can be overdone. Well, sort of. What I have in mind is the following from How to Do What You Love:
A friend of mine who is a quite successful doctor complains constantly about her job. When people applying to medical school ask her for advice, she wants to shake them and yell "Don't do it!" (But she never does.) How did she get into this fix? In high school she already wanted to be a doctor. And she is so ambitious and determined that she overcame every obstacle along the way — including, unfortunately, not liking it.
Now she has a life chosen for her by a high-school kid.
I think some people might get so good at pushing past things that they forget to ask whether the thing is something they even should push past in the first place.
I feel like (2) is usually more appropriate than (1) [...] It usually makes sense to make the thing easier than to improve your ability to push past it.
I agree with this as a long-term strategy for dealing with repetitive problems. And I share the suspicion that "tough" people often have it easier (which may or may not be a result of their previous actions).
But sometimes life throws an unexpected thing on you, and then you roll for "toughness" or fail. (Though maybe you can also prepare for the unexpected by practicing many different things, thereby increasing the chance that some skill you have will be relevant for the new situation.)