When Men Behave Badly

Key Takeaways

1. Sexual conflict is an evolutionary arms race between males and females

For every tactic one sex evolves to exploit the other, there exists at least one coevolved defense in the other.

Antagonistic coevolution. Sexual conflict theory proposes that males and females have evolved competing adaptations to influence reproduction in their own favor. This results in an evolutionary arms race, with each sex developing new strategies to gain an advantage, which are then countered by the other sex. For example:

• Males evolve persistence in pursuing mates, females evolve choosiness
• Males evolve larger body size for mate competition, females evolve ways to assess male quality beyond size
• Males evolve sperm competition tactics, females evolve ways to control sperm use

This conflict extends beyond mating to areas like parental investment, with each sex evolving ways to extract more care from the other while minimizing their own investment. Understanding this evolutionary dynamic provides insight into modern relationship conflicts.

2. Men's desire for sexual variety is a key source of conflict

Men said they wanted 1.87 sex partners over the next month; women expressed a preference for only 0.78, a bit less than a full sex partner.

Mismatch in sexual desires. Men's greater desire for sexual variety is one of the largest and most robust sex differences in psychology. This difference creates conflict because:

• Men are more likely to seek casual sex and short-term relationships
• Men are more prone to sexual infidelity
• Men are more likely to misperceive friendly behavior as sexual interest

This mismatch in desires stems from different reproductive constraints faced by men and women over evolutionary history. For men, multiple partners could directly increase reproductive success. For women, quality of partner was more important than quantity. This evolved difference continues to shape relationship dynamics and sexual conflicts today.

3. Mate value discrepancies fuel relationship struggles

Women married to higher-income men display more vigilant guarding and put more effort into enhancing their own physical attractiveness through makeup and clothing, although this may simply reflect having more money to spend on these items.

Relationship power dynamics. Differences in mate value between partners can create tension and conflict. The partner with higher mate value may:

• Have more power in the relationship
• Be more likely to pursue alternative partners
• Inspire more jealousy and mate retention behaviors from their partner

Mate value is influenced by factors like:

• Physical attractiveness
• Resources and status
• Age and fertility
• Personality traits

When mate values shift during a relationship (e.g. one partner gains status or loses attractiveness), it can destabilize the dynamic. Understanding these influences can help couples navigate changes and conflicts more effectively.

4. Intimate partner violence stems from evolved mate retention tactics

Male sexual jealousy is the leading cause of the murder of adult women, accounting for between 50 and 70 percent of all such homicides.

Dangerous possessiveness. While most men do not use violence, intimate partner violence can be understood as an extreme and maladaptive expression of evolved mate retention tactics. Key points:

• Violence is more likely when men perceive a threat to the relationship
• Triggers include suspected infidelity and attempts by the woman to leave
• Pregnancy can increase risk of violence, possibly due to paternity uncertainty
• stepchildren in the home increase risk, as they represent a cost without genetic benefit

This perspective helps explain patterns in domestic violence, like increased risk during separation. However, it does not justify or excuse such behavior. Rather, understanding these impulses can inform more effective prevention and intervention strategies.

5. Stalking behaviors serve reproductive functions for rejected partners

A full 30 percent of women victims agree to meet with their stalkers at their request; 13 percent agree to date them; and 6 percent agree to have sex with them.

Maladaptive persistence. Stalking behaviors, while harmful and often illegal, may have roots in evolved mate retention strategies. Key aspects:

• Most stalkers are rejected former romantic partners
• Stalking tactics resemble intense mate guarding behaviors
• Goals often include reconciliation or preventing the ex-partner from mating with others

Stalking exploit's victims' psychology through:

• Consuming the victim's time and mental resources
• Social isolation
• Creating a negative reinforcement cycle where compliance provides relief

While stalking sometimes "works" from the perpetrator's perspective, it imposes severe costs on victims. Understanding stalking's functional basis can inform better prevention and protection strategies.

6. Sexual coercion exploits women's evolved defenses against rape

Men who score high in Dark Triad traits are much more prone to sexual coercion, especially when combined with the persistent pursuit of a short-term mating strategy.

Predatory exploitation. While most men are not rapists, those who engage in sexual coercion exploit aspects of women's evolved psychology, including:

• Women's tendency to freeze in threatening situations (tonic immobility)
• Fear of reputational damage from reporting assaults
• Difficulty distinguishing coercive from normal courtship in some contexts

Factors increasing risk of perpetration:

• Dark Triad personality traits (narcissism, Machiavellianism, psychopathy)
• Short-term mating orientation
• Hostile attitudes toward women

Understanding these risk factors and how coercion exploits women's defenses can inform better prevention, education, and support for victims.

7. Cultural evolution can help reduce sexual conflict

The rates of physical and sexual violence within mateships have declined dramatically over spans of decades.

Societal progress. While sexual conflict has deep evolutionary roots, cultural evolution offers ways to reduce its harmful expressions:

• Legal reforms criminalizing marital rape and workplace harassment
• Changing social norms that condemn sexual violence and coercion
• Economic changes giving women more independence and options

Examples of progress:

• Declining rates of intimate partner violence in many countries
• Increased reporting and prosecution of sexual crimes
• Workplace policies against sexual harassment

Cultural shifts can change the cost-benefit calculus of sexually coercive behaviors, suppressing their expression even if the underlying psychology remains.

8. Individual differences in Dark Triad traits predict sexual aggression

High-scoring Dark Triad men are more likely to glare at other men who are talking to their mate and threaten them with physical violence—a topic we take up in greater detail in Chapter 5.

Dangerous personalities. While evolutionary psychology explains general patterns in male behavior, individual differences in personality traits strongly predict who is most likely to engage in sexual aggression. Key points:

• Dark Triad traits: narcissism, Machiavellianism, psychopathy
  These traits are associated with:
  • Sexual deception and manipulation
  • Coercive and aggressive mating tactics
  • Higher rates of infidelity and mate poaching

Understanding these individual differences can help identify high-risk individuals and inform targeted interventions. It also highlights that most men do not pose a significant threat of sexual aggression.

9. Women have evolved multi-layered defenses against sexual coercion

Women's rape fears track their age-linked vulnerability suggests that their anti-rape psychological wisdom may be a better guide than factually incorrect educational materials, however well intended those may be.

Adaptive vigilance. Women have evolved a suite of defenses against sexual coercion, including:

Psychological defenses:

• Fear and vigilance in high-risk situations
• Intuitive threat detection
• Tonic immobility (freezing) when escape is impossible

Behavioral defenses:

• Avoiding risky situations
• Traveling in groups
• Seeking protection from male allies

Social defenses:

• Reputational concerns limiting risky behavior
• Coalitions with other women for mutual protection

These evolved defenses help explain patterns in women's behavior and fears around sexual assault. While not always consciously accessible, they often provide good guidance for avoiding dangerous situations.

10. Minding the gap in sexual psychology can foster harmony between sexes

Men need to understand the sexual over-perception bias that afflicts their mating minds. They should know that, most of the time, the women smiling at them are merely being friendly or polite, not signaling sexual interest.

Bridging understanding. Recognizing and respecting differences in male and female sexual psychology can reduce conflict and misunderstanding. Key points:

• Men tend to overperceive sexual interest from women
• Women experience greater emotional distress from sexual violations
• Men and women have different emotional reactions to casual sex

Strategies for harmony:

• Education about these differences for both sexes
• Developing empathy for the other sex's perspective
• Creating cultural norms and institutions that respect these differences

By "minding the gap" in sexual psychology, we can develop more effective ways to reduce sexual conflict and foster healthier relationships between men and women.

Last updated: May 12, 2025

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