We're all made of the same stuff as everyone else. You can point to mini-differences in our DNA but really, that makes us separate? If you looked at two trees that were 98 or 99% alike, would you think of them as disparate, or part of the same family?
We are a convention of tiny particles of energy that never forget: if one particle meets up with another, even for a nano-second, a life-long bond is formed. The one will always have an effect on the other no matter how far apart in space. We're made of these particles.
The language of emotions is hardwired into all of us. A sad expression is the same in Asia or Europe; that is true for anger, fear, happiness, etc. On an emotional level, we all experience and express life the same way. Emotionally, we know everyone on the planet very well.
All people breath air in, and a byproduct out. On the surface that's a "duh" statement. If you ponder it, it's not a stretch to consider humans as cells of one breathing body. We don't each have our own air supply. We share what goes in and comes out.
Cultural differences impact what people find funny, but humans have a sense of humor. We laugh at life's absurdities (and while laughing, we are sucking-in and hee-hawing out the same air supply). Laughing has always been considered good for health of human beings everywhere, and we all enjoy it.
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