1. Sex Differences in Jealousy:
Evolution, Physiology, and
Psychology
Buss, Larsen, Westen, and Semmelroth

2. Paternity Uncertainty

3. Potential Loss of Investment

4. The Answer is . . .

6. “(...) a state that is aroused by a perceived threat to a valued
relationship or position and motivates behavior aimed at
countering the threat.” (Buss et al., 1992)

7. “Men indifferent to sexual contact between their mates and
other men presumably experienced higher paternity
uncertainty, greater investment in competitors’
gametes, and lower reproductive success”
than did men who were motivated to attend to cues of
infidelity and to act on those cues to increase paternity
probability.” (Buss et al., 1992)
Therefore, over time, evolution through
means of natural selection managed to
“choose” jealous men over the not so
jealous.

8. General Hypothesis: The experience of
jealousy is felt differently for men and
women because of the different adaptative
problems posed to both sexes.
Distinction between sexual
and emotional infidelity.

9. Study 1
N=202 undergraduate students
(a) Imagining your partner forming a deep
emotional attachment to another person.
(emotional infidelity)
(b) Imagining your partner enjoying passionate
sexual intercourse with another person.
(sexual infidelity)

10. • 60% of the male sample chose partner’s
potential sexual infidelity in comparison to only
17% of the female sample (p < .001)
• 83% of the female sample chose partner’s
potential emotional infidelity as the most
worriesome of the two options.

11. Study 2
GOAL: To confirm the previous hypothesis through the use
of physiological measures.
Measures of autonomic arousal:
– Electrodermal Activity (EDA) via skin conductance;
– Pulse Rate (PR);
– Electromyographic (EMG) activity of the corrugator
supercilii muscle.

12. Electrodermal Activity
• Men showed significant increases in EDA during
the sexual imagery compared with the emotional
imagery (p < .0.5)
• Women showed significant increases in EDA to
the emotional infidelity image than to the sexual
infidelity image (p < .05)

13. Pulse Rate
• Men showed increase in PR to both images, but
significantly more so in response to the sexual
infidelity image (p < .05)
• Women showed elevated PR to both images, but
not differentially so.

14. Brow Contraction
• Men showed greater brow contraction to the
sexual infidelity image, and women showed the
opposite pattern (non significant, p < .13, p <
.12)

15. Study 3
GOAL:
Replicate and extend the results of the two previous studies
by incorporating the experience of being in a committed relationship.
Results:
• Highly significant differences for men but not for women.
• 55% of the men who had experienced a committed
relationship reported more distress for sexual infidelity
whereas only 29% of the men that didn’t experience it felt
distressed by it.

16. Critical Limitations
• Undergraduate students
• No clear-cut distinction – Emotional vs. Sexual
• Imagined Infidelity ≠ Actual Infidelity
• Swinging (maybe?)