I do think that we are socialized to expect that labor is painful and frightening - and therefore, many women go into the experience expecting (and fearing) that.
When we are scared, sensations are more vivid IMO. So, we are scared - and that magnifies the pain we're experiencing.
NOT that that happens for everyone. Mom had 7 of us. She told me, "Labor is like menstrual cramps." And, honestly - that's pretty much what it was like for me. I'd wondered whether she and my sister were sugarcoating it, but really it was like that for me. Despite back labor with Ina, it still wasn't *that* painful. Maybe it helps that my family tends to have quick labors, too ...? I've certainly experienced more pain (like, afterwards, my tailbone KILLS for several weeks/months).
And, I wouldn't say I'm 'tough' or have a high pain threshold. I have a very tender mouth, I hate going to the dentist for instance.
I think the keys are to really understand/know what happens during labor, to mom and baby - what to expect from your support team - and to think through what you'll need (and recognize that you may not "know" til you're there, so do lots of research). I'd read that lots of women become prickly and don't want to be touched etc. towards the end of their labor - not for me. DH hoped (and fortunately was correct) that humor would help me relax .... we talked about what I'd read *might* happen in terms of not wanting to be touched or etc., but just relaxed and went with it and were fine.
I tell moms - relax. Do your research, take some classes if they're available, write a birth plan, and remember - women have been doing this since the beginning of time. So we can do this!! Relax, relax, relax.
I do know it hurts more when I don't consciously relax - when I was being distracted by staff at dd2's birth (I have a heart condition and require an IV) - the contractions were much more painful than when I stopped, refocused, and embraced the contraction/relaxed.
Mom said one of the OBs she had over the years tried to get her to do hypnobirth (he did it with many patients) but she didn't do it ever - NCB'd all 7 of us.