1. Decreased Oxytocin. In my page discussing the Potential Risks of Testosterone, I discuss that as one increases testosterone oxytocin appears to decrease. Of course, oxytocin is known as the empathy and bonding hormone. Therefore, those with an anti-testosterone bias, are quick to point to this factoid.
2. Decreased Brain Connections in Empathy Regions. There is some evidence that testosterone lowers the number of connections in the area of the brain where empathy is expressed most actively:
3. Testosterone and DHT Lower Generosity. One study looked at how much generosity was exhibited during the “Ultimatum Game” and found the following:
“Men in the lowest decile of DHT were 560% more generous than men in the highest decile of DHT. We also found that men with elevated testosterone were more likely to use their own money punish those who were ungenerous toward them. Our results continue to hold after controlling for altruism. We conclude that elevated testosterone causes men to behave antisocially.” 
Since the authors of this study go on to point out that past research has linked generosity to empathy, the conclusion that they want you to come to seem obvious, eh?
REBUTTAL: Sounds horrible, doesn’t it? One of the most important traits for relationships is empathy – being able to feel the emotions of others – and a complete lack of empathy is well known as one of the hallmark behaviors of psychopaths. Upon first glance, it would sound as if testosterone was, frankly, somewhat evil – antisocial as study #4 termed it.
The evidence actually shows that normal, physiological levels of testosterone and DHT in men are associated with significant empathy, perhaps as much as females.
Let’s start with study #3. They showed that men in lowest decile of DHT were 5.6 times more generous than men in the highest decile of DHT. What they don’t tell you is that, if you pull up the charts in that study, the top decile of DHT in that study is about 1575 – 1750 pg/ml. This is very high DHT. Typical lab ranges for healthy adult males are 300 – 900 pg/ml. Yes, you read that right: this study drew conclusions from men that were twice the top of the lab range for a health young male!
Now I have no doubt that these researchers knew what they were doing, because they gave the men Androgel. Any topical / transdermal testosterone cream / gel will jack up DHT levels artificially and the above results are both expected and common – I see it all the time on the Peak Testosterone Forum for example. This is one of the reasons that I am cautious about transdermals.
And, if you look at study #2, one should realize that the study was actually on women. And, while it is true that testosterone probably affects brain connections in many key ways, some research shows that normal testosterone levels do not affect empathy.  Still other research shows that men are just as good at empathy if they are told to be empathetic.
“Jamil Zaki, assistant professor of psychology at Stanford University and director of the university s social neuroscience laboratory,…points to studies where men and women were given a test designed to assess their ability to read other people s emotions. Some of the participants were told beforehand that they were taking an empathy test and some weren’t. When the participants were told what kind of test it was, women did better than men. But when the participants weren’t told, the men did just as well.” 
In other words, the root issue of any lack of empathy in us guys isn’t hormones but rather that society has taught us not to be empathetic.
My personal takeaway from this research is simply the following:
a) This is yet another reason that one does not want to go supraphysiological with testosterone and possibly DHT.
b) Men must guard against cultural and familial influences to avoid empathy.
c) Normal testosterone and DHT levels do not hinder empathy assumping empathy is taught.
1) Social Neuroscience, 2006, 1(2), “Fetal testosterone and empathy: Evidence from the Empathy Quotient (EQ) and the Reading the Mind in the Eyes Test”
2) Psychoneuroendocrinology, Jun 2016, 68:194 201, “Testosterone reduces functional connectivity during the Reading the Mind in the Eyes Test”
3) Personality and Individual Differences, Dec 2006, 41(8):1481 1491, “Lack of correlation between digit ratio (2D:4D) and Baron-Cohen s Reading the Mind in the Eyes test, empathy, systemising, and autism-spectrum quotients in a general population sample