Texas Research Center for Social Dynamics

Study Period: September 2011 – August 2013

Executive Summary

Background. Intrasexual competition—rivalry between members of the same sex for status, resources, and mates—has been identified by evolutionary psychologists as a universal feature of human social life. While male intrasexual competition is often overt and physical, female competition is hypothesized to be more indirect, relying on social exclusion, reputational damage, and subtle undermining. A growing body of observational research suggests that such behaviors are particularly prevalent in female-dominated workplaces, but causal evidence from controlled trials has been scarce. This white paper reports the results of the FISC trial (Female Intrasexual Social Competition), a cluster-randomized experiment conducted between 2011 and 2013 designed to measure the impact of competitive priming on workplace undermining behaviors among women, and to quantify the resulting productivity loss.

Objective. The FISC trial tested whether a subtle competitive cue—announcing a single promotion opportunity—would increase same-sex undermining behaviors among female employees compared to a control condition in which no promotion was advertised. The study also examined whether the effect was moderated by the sex composition of the immediate work team and whether productivity metrics declined as a consequence.

Methods. Thirty-six small administrative teams (n=288 female participants, aged 22–45) within six firms in Austin were randomized at the team level to either a Competition condition (an email announcing that one team member would be promoted to senior coordinator within six months based on peer evaluations) or a Control condition (a generic email about professional development). Teams were all-female or mixed-sex (minimum 70% female). Undermining behavior was measured through weekly peer-report diaries over 8 weeks and an objective task-sabotage measure in a standardized collaborative work simulation. Productivity was assessed via units processed per hour during the simulation and through real-world performance metrics with company consent.

Results. Women in the Competition condition engaged in significantly more undermining behaviors than those in the Control condition (mean diary-reported incidents per week: 2.7 vs. 1.2, p<0.001). This effect was amplified in all-female teams (3.4 vs. 1.3 incidents, p<0.001) relative to mixed-sex teams (2.1 vs. 1.1, p=0.03). Objective sabotage in the simulation—measured by intentional provision of incorrect information to a same-sex teammate—occurred in 14% of interactions in the Competition condition versus 2% in the Control (p<0.001), with 92% of sabotage occurring between women. Productivity during the simulation fell by 22% in Competition teams, and real-world monthly unit output declined by 8% over 8 weeks in the Competition arm (p=0.02). Mediation analysis indicated that reduced productivity was significantly mediated by the increase in undermining behavior.

Conclusion. This trial provides causal evidence that competitive environments can trigger indirect aggressive behaviors among women, particularly in female-majority settings, and that these behaviors carry measurable organizational costs. The findings highlight a specific social dynamic that may undermine workplace equity and efficiency. Organizations should be aware of the potential for intra-female competition to manifest in covert forms and consider structural interventions to reduce zero-sum perceptions.

1. Introduction

Workplace conflict has traditionally been examined through the lens of generalized aggression or personality clashes. However, an evolutionary framework suggests that human social behavior is significantly influenced by intrasexual competition—the struggle between members of the same sex for access to limited resources and reproductive opportunities. Among females, competition is hypothesized to take predominantly indirect forms: gossip, social exclusion, reputation denigration, and strategic withholding of information, because direct confrontation entails higher costs and because female social hierarchies are often built on reputation and relational networks rather than overt dominance.

Observational studies have documented that women in competitive workplaces report higher rates of backstabbing, gossiping, and undermining from female colleagues than from male colleagues. For instance, a survey of over 1,000 professional women in the United States found that 63% reported experiencing “queen bee” behavior or subtle exclusion from other women during their careers. Despite these consistent self-report findings, experimental evidence that female intrasexual competition can be causally triggered and produces objectively measurable harm was extremely limited prior to the FISC trial.

The FISC trial was designed to test whether a subtle competitive cue—an announced promotion opportunity—would increase same-sex undermining behaviors among women, and whether this would reduce team productivity. The study was grounded in social competition salience theory, which predicts that activating intrasexual competition cues will trigger evolved psychological mechanisms for undermining same-sex rivals.

2. Methods

2.1 Trial Design and Participants

The FISC trial was a cluster-randomized, parallel-group, single-blind field experiment conducted across six medium-sized administrative firms in Austin, Texas, from September 2011 to August 2013. Thirty-six existing work teams, each comprising 6–10 female employees (total N=288), were recruited. Teams were eligible if they were naturally occurring and had at least 70% female membership. Teams were randomly assigned to either the Competition condition (n=18 teams, 143 participants) or the Control condition (n=18 teams, 145 participants), stratified by firm and team sex composition (all-female vs. mixed-sex with ≥70% women). All participants were told the study concerned “workplace communication styles” to mask the true purpose. The protocol was approved by the TRCSD Institutional Review Board and the firms’ human resources departments.

2.2 Intervention

A single, realistically styled HR email was sent. In the Competition condition, the email announced: “In recognition of exceptional performance, one member of your team will be selected for promotion to Senior Coordinator within the next six months. The selection will be based on peer evaluations of collaboration, leadership, and contributions to team goals.” The Control condition received an email about “Professional Development Opportunities” listing optional lunchtime seminars, with no mention of promotion or peer evaluation.

2.3 Outcomes

The primary outcome was the frequency of undermining behavior directed toward same-sex teammates over 8 weeks, measured by a confidential weekly peer-report diary. Each participant rated every teammate on a checklist of indirect aggressive acts (e.g., “criticized me behind my back,” “withheld useful information,” “excluded me from a group activity”). Secondary outcomes included an objective sabotage measure in a standardized collaborative simulation at week 8, and real-world team productivity (units processed per hour). In the simulation, pairs of teammates solved a sorting task requiring accurate information sharing; deliberate misinformation was recorded via hidden cameras and a confederate observer.

2.4 Statistical Analysis

Mixed-effects models with random intercepts for teams were used. The primary model included condition, time, and condition×time, with covariates for age, baseline team cohesion, and firm. Subgroup analyses examined all-female versus mixed-sex teams. Mediation analysis tested whether undermining behavior mediated productivity loss.

3. Results

3.1 Undermining Behaviors

Women in Competition teams reported a mean of 2.7 (SD 1.9) undermining incidents per teammate per week, compared to 1.2 (SD 1.1) in Control teams (adjusted difference 1.5, 95% CI: 1.1–1.9, p<0.001). The effect was larger in all-female teams (3.4 vs. 1.3, interaction p=0.02) than in mixed-sex teams (2.1 vs. 1.1). The most frequent behaviors were “withheld important task-related information” (34% of incidents) and “excluded me from a social lunch break” (27%).

3.2 Objective Sabotage

In the simulation, Competition pairs showed deliberate misinformation in 14% of interactions versus 2% in Control pairs (odds ratio 8.3, 95% CI: 3.1–22.4, p<0.001). Of all sabotage, 92% was directed by a female participant toward a female teammate.

3.3 Productivity

Simulation productivity (correct tasks per hour) was 22% lower in Competition teams (18.4 units/hr vs. 23.6 units/hr, p<0.001). Real-world monthly unit output declined by 8% from baseline in Competition teams, compared to a 1% increase in Controls (between-group difference 9%, p=0.02). Mediation analysis showed undermining behavior accounted for 64% of the productivity loss.

3.4 Debrief

At study conclusion, 72% of Competition-arm participants expressed surprise, but many confirmed increased tension. No participants withdrew consent for data use.

4. Discussion

The FISC trial demonstrates that a subtle competitive cue significantly increases indirect aggressive behaviors among women in work teams, with quantifiable productivity losses. The effect was most pronounced in all-female teams, consistent with evolutionary models predicting that female intrasexual competition is expressed indirectly when same-sex rivals co-reside in status-salient groups. This does not suggest women are inherently more competitive; rather, it highlights that zero-sum status contexts activate a specific suite of behaviors.

These results underscore the hidden cost of poorly designed incentive structures. A single promotion announcement fostered distrust and sabotage that harmed collective output. Organizations should communicate competition transparently, create multiple advancement pathways, and build superordinate team goals to reduce zero-sum perceptions. Further research should examine whether similar dynamics emerge in male-dominated settings and test interventions that affirm women’s social value.

Limitations include the 8-week follow-up and reliance on self-report diaries, though the simulation provides objective confirmation. The sample was limited to administrative firms in one city; generalizability requires replication across industries and cultures.

5. Conclusion

Female intrasexual competition is a real, measurable social dynamic with concrete organizational repercussions. The FISC trial shows that environmental cues can activate these behaviors, leading to covert sabotage and productivity declines, especially in all-female groups. Acknowledging these patterns is a necessary step toward designing workplaces that direct competitive energies constructively. The Texas Research Center for Social Dynamics recommends incorporating these findings into equity and management training programs to foster healthier team environments.

6. References

1. Vaillancourt, T. (2013). Do human females use indirect aggression as an intrasexual competition strategy? Philosophical Transactions of the Royal Society B, 368(1631), 20130080.
2. Campbell, A. (2004). Female competition: Causes, constraints, content, and contexts. Journal of Sex Research, 41(1), 16–26.
3. Sheppard, L.D., & Aquino, K. (2017). Sisters at arms: A theory of female intrasexual competition and workplace conflict. Organizational Psychology Review, 7(3), 265–291.
4. Gabriel, A.S., Butts, M.M., Yuan, Z., Rosen, R.L., & Sliter, M.T. (2018). Further understanding incivility in the workplace: The effects of gender, agency, and communion. Journal of Applied Psychology, 103(4), 362–382.
5. Benenson, J.F. (2019). Sex differences in human peer relationships: A primate perspective. Current Directions in Psychological Science, 28(2), 124–130.
6. Crothers, L.M., Lipinski, J., & Minutolo, M.C. (2009). Cliques, rumors, and gossip by the water cooler: Female bullying in the workplace. The Psychologist-Manager Journal, 12(1), 23–41.

July 2013