This implies that the jealousy trait is in fact not evolutionary, since it is not always the same reaction (DeSteno, et al., 2002). In addition, DeSteno also found that, while women showed a slight tendency to rate emotional infidelity as worse than sexual infidelity, they did not differ from men on sexual infidelity ratings alone. When asked to rate the level of distress due to sexually infidelity, without comparing it to emotional infidelity, men and women rated the distress the same (DeSteno, et al., 2002). This implies that while women may be more distressed then men at emotional infidelity, there is no difference between the sexes in levels of distress for sexual infidelity alone.

In fact, even studies which purport to support the theory that men are more jealous than women show similar results to those of DeSteno. Buss and his colleagues' study in 1992 reported a difference in male and female jealousy ratings. However, when examined, only electrodermal skin activity and pulse rate differed between men and women in the study. Brain activity between men and women did not differ (Buss, et al., 1992). According to DeSteno, this result means that while the findings may indicate some level of differences, true arousal state of the subject cannot be verified. Since skin and pulse data change in men viewing sexual activity regardless of the nature of that activity, it is impossible to determine if that reaction is negative in nature (DeSteno, et al., 2002).

In her research, Harris also points to studies showing that men are more likely to kill their partner or their partner's lover in response to jealousy. According to Harris, it is important to realize that men are more likely to commit all violent crime. Thus, comparisons of the number of men who commit violent crime as a result of jealousy to the number of women who do the same are invalid. Instead, Harris says, the true comparison should be that of the proportion of homicide committed by men due to jealousy to that of women. When this is done, Harris states, women are shown to be just as likely as men to commit acts of violence in response to jealousy (Harris, 2004).

Other studies have also shown the idea that men are more jealous to be incorrect. In three separate studies, Catherine Harris tested the idea that men are more jealous. In the first study, Harris measured the blood pressure and heart rate of women and men. Those subjects were instructed to imagine actual scenarios of sexual or emotional infidelity by their partners. While men showed a greater physical reaction to sexual infidelity, women reacted almost identically to both the sexual and emotional infidelity. When compared to the males, the females showed a tendency to react in similar ways (Harris, 2004).

Recognizing that men react to sexual stimuli regardless of scenario, Harris went on to examine whether or not the higher male response was due to the sexual stimuli alone. Harris retested subjects, only this time removed the infidelity aspect of the study. Harris then tested the male and female responses to imagine scenarios again. This time, Harris altered the scenario to be one in which the male or female had sex and fell in love with their partners. The males again showed a higher body reaction than the women, confirming Harris's theory that the male body was responding to the sexual imagery, not the scenario (Harris, 2004).

In a follow-up study, Harris also tested women to verify their verbal reaction to infidelity. In this study, subjects were asked to determine which would be most distressful, emotional or physical infidelity. Harris found that while women believed emotional infidelity would be more distressing, their physical responses to both scenarios were equal. Additionally, Harris found that those women involved in a committed relationship showed a much higher reaction to sexual infidelity...

Additionally, both studies showed that previous attempts to discover the more jealous sex were flawed, in that the methods used were biased towards men being more jealous than women. Criminal studies are biased, in that men are proportionately more likely to commit crime to begin with, even before introducing jealousy into the equation. Self-report studies rely on comparison data that can be leading for the subject, and force them to choose an answer, which can lead to incorrect results. Additionally, self-report studies rely on the knowledge of the subject as to how and to what extent emotions are felt, which can also be incorrect.
Recent studies have shown that more research is needed on the differences between male and female response to jealousy. The studies of Harris and DeSteno show at least a hint of evidence that previous results showing a difference between male and female jealousy levels are incomplete, at best. Furthermore, these studies show promising evidence that men and women's levels of jealousy and responses to jealousy may be far more related than previously thought.

When all research is combined, it becomes clear that jealousy is more than just an evolutionary trait. A person's reaction to jealousy may be in part due to evolution, but may also be related to a person's prior experience, level of relationship capability, gender, and many other factors. It is only by studying jealousy from all angles and without bias that the true nature of the emotion can be determined. However, it is clear that men are not, contrary to historical belief, more jealous than females.