Something that I’ve always found interesting is the different levels of pain people are able to endure.  Most of the people in my family are extremely good about tolerating pain, in fact my dad broke 4 ribs and didn’t want to go to the doctor because he felt that it would just be a nuisance.  (Don’t ever do this)  So I wanted to know why is everyone able to withstand different amounts of pain, and what are the causes behind it.  I focused my research mainly on genetics, because there is an already documented difference between genders.  The null hypotheses here would be that genetics don’t play a role in pain tolerance, and the alternative would be that they indeed do.

Background

To understand why people have different levels of pain tolerances, I think it’s first important to understand what causes us to feel “pain” as we know it.  In a very general description, pain is caused by μ-opioid receptors in our central nervous system.  When the body receives these signals, it tells the brain that we are experiencing something that is causing pain to our body.  I also learned that this is how pain-killers work, things like morphine suppress that receptor so that the signals of pain aren’t sent to the body (

Study

The first study that I chose to look at was one about different ethnicities having differing levels of pain tolerance.  The study I am using for this was conducted by Robert Edwards in which he analyzed the levels of pain reported by peoples of different ethnicities.  The findings of his study were that African American patients reported higher levels of debilitating pain.  They also did a test to see how long patients could withstand restricted bloodflow to their arms, and on average White patients were able to withstand the pain for 9 minutes while African American patients were only able to cope for 5 minutes.  This is a pretty significant gap and shows a large potential area for differences between ethnic groups.

Pain levels reported by various ethnic groups Source

In a study by Christopher Nielsen that dives more into how genetics affect our pain tolerances, he concludes that 60% of the difference in pain felt from extreme cold is genetic and 28% of the difference when its extreme heat is genetic.  This study concluded that a large part of pain tolerance is inherited as offspring, and that it plays a slightly larger part in pain tolerance then your environment does.  This study showed that there was more of a link between genetics and pain tolerance then was previously believed.  However, this study by Mark Litt asserts that one of, if not the largest, indicators of pain levels is a persons mental state.  If the subject expected there to be extreme pain, they were more likely to feel it then someone who didn’t expect major discomfort.

Conclusion

From reading these studies, I’ve come to the understanding that you can’t really pin pain tolerance on just one or two different things.  The evidence shows that the alternative hypothesis was correct, and that genetics do play a role in it.  But there’s more to it then that, things like gender, ethnicity, and psychology also play a major role.  I would say this is about what I expected to find from this research aside from the fact that I never really took the mental aspect into account.  Since there’s no way to pin our tolerance on one specific thing, it’s fair to say that people who can withstand large amounts of pain have a lot of different things going for them.