In one study, subjects were given what they erroneously believed to be a mood 'fixing' drug -- "empathic subjects were more helpful than their nonempathic counterparts only when it seemed possible that their personal moods could be raised as a consequence of helping. High-empathy subjects who learned that their saddened mood states could not be altered by the helping act (because of the temporary action of a "mood-fixing drug") did not help at enhanced levels, despite their still-elevated empathic-concern scores" (Cialdini et al. 1987, p. 757). The proposition of a financial reward in exchange for nonempathetic behavior also reduced the subject's generosity -- the selfish pleasure from the reward reduced the selfish desire to reduce the anxiety from 'doing nothing,' Cialdini hypothesized. Interestingly, only female subjects were used in the test, and Cialdini notes that they were psychology students. This raises several questions: firstly, might male and female empathic responses differ? Also, the idea of a 'mood stabling drug' seems to lack credibility to some extent, and perhaps the students might suspect that they were being lied to, given their experience with basic psychology. The same might be true with Batson's subjects, especially given the famed Stanley Milgram experiments involving electroshock therapy, which were also conducted under false pretexts.

There is a further problem with defining empathy in a narrow, either/or fashion, as either predominantly a sense of identification with the subject or predominantly a way of relieving one's own psychological distress. The feelings...

Another question is if there are different types of empathy that are aroused in terms of emotional or physical pain, which might be experienced in a very different fashion, as one requires more complex 'as if' thinking. Bateman used one study involving physical pain and another involving emotional pain, and used the two types of empathetic feelings aroused by these different scenarios as relatively exact comparisons.
One way to make the tests more useful in this respect for finding truly empathetic subjects might be to use a larger cross-section of the population, and include a group of subjects who had performed empathetic actions or were in empathetic professions that required apparent self-sacrifice such as firemen. Interviews with altruistic subjects would possibly suggest a more complex balance of identification and self-serving behavior. Regardless, both studies seem too small to provide a final answer as to what is the origin of human empathy.

Works Cited

Batson, Daniel; Bruce D. Duncan; Paula Ackerman; Terese Buckley; & Kimberly Birch. "Is empathic emotion a source of altruistic motivation?" (1981). Journal of Personality and Social Psychology. 40

Cialdini, Robert B.; Mark Schaller; Donald Houlihan; Kevin Arps; Jim Fultz, & Arthur L.

Beaman. (1987). Empathy-based helping: Is it selflessly or selfishly motivated? Journal

of Personality and Social Psychology. 52(4), 749