Why do people have different levels of empathy?

Never assume others feel like you do. And never assume they don’t. Never make up your mind about others based on yourself and those you have encountered. You can learn behaving like an empath, but you cannot acquire sensitivity. It is important to know that while empathy is a great thing, one needs to protect oneself from those who have less of it. Rh negatives appear to test high for the trait. If you are surrounded by people who lack it, learn to shut yourself off as needed, but don’t try to kill the trait that will serve you well when in the company of those who share it.

According to this German article, women are more likely to be empaths than men are:

It was first confirmed that women are more empathetic than men. The heritability of the trait was equally pronounced for both genders: the level of the score achieved in the eye test was 5.8 percent attributable to certain genetic traits. An additional analysis of data from a group of 1500 twins and twins showed an even more significant result with a heredity of empathy capacity of 28 percent. In the female genome, not the men, the researchers also found on chromosome 3 a section of DNA that was closely related to empathy. There are indications that this affects a gene that is particularly active in the brain region of the striatum.