Estrogen and Cooperation, Competitiveness, and Risk Preferences

This study observes the effects of female cycle hormones on cooperation, competitiveness and risk preferences under experimental conditions. Especially, the causal effect of estradiol is isolated.

Behavioural theories assume that, as a result of natural selection, women undergo a brief, unconscious change in some psychological aspects during ovulation. This short-term change, "ovulatory shift", is assumed to aim to increase the probability of successful reproduction in the decisive days of the female cycle. Amongst others, it is assumed that women behave particularly uncooperatively and particularly competitively towards other women during the fertile days. Though, empirical evidence is ambiguous.

The effect on risk preferences is unclear. Theory generally assumes that female risk aversion increases in the fertile days. However, empirical studies find partly positive and partly negative correlations.

Within the scope of this study, estradiol levels which are collected in the clinical treatment of patients in the Clinic for Gynaecological Endocrinology and Reproductive Medicine are to be linked with the behavioural economic measures of cooperation, competitiveness, and risk preferences, which are collected using questionnaires or a computer-based decision task.

The aim of the research project is to quasi-experimentally isolate the effect of estradiol on competitiveness, cooperation and risk preferences of women.

No study known to us has ever been able to realize a comparable quasi-experimental design which is necessary to isolate the causal effect of estradiol on different behavioural measures.

In the experimental group, a sample of approx. 50 women in fertility treatment (In Vitro Fertilization/Intracytoplasmic Sperm Injection (IVF/ICSI), long Gonadotropin releasing Hormone (GnRH) agonist protocol) is surveyed. This allows us to create a quasi-experimental design in which the estradiol level is exogenously manipulated and regularly measured.

A random sample of 30 male students of Rheinisch-Westfälische Technische Hochschule (RWTH) Aachen University serves as a control group.

We realize a longitudinal section design with measurement repetitions, which allows inter- and intrapersonal comparisons. A three-stage procedure with two measuring points and a preliminary clarification meeting is planned.

The following measuring instruments are used to record competitiveness, cooperation and risk preference: SOEP Risk Attitude, Social Value Orientation German A, The cooperative and competitive Personality Scale German, Risk aversion, Willingness to compete.

Eligibility Criteria:
Inclusion Criteria:

Patients

1. female
2. patient in fertility treatment according to Long GnRH Agonist Protocol
3. 18 years and older
4. written declaration of consent
5. persons who are contractually capable and mentally able and willing to follow the instructions of the study staff
6. understanding of the German language (written and spoken)

Control group

1. male
2. 18 Years and older
3. written declaration of consent
4. persons who are contractually capable and mentally able and willing to follow the instructions of the study staff
5. understanding of the German language (written and spoken)

Exclusion Criteria:

Patients

1. Illiterate
2. pregnant and breastfeeding women
3. persons who are accommodated in an institution on official or court order
4. persons in a dependent or employment relationship with the auditor
5. simultaneous participation in another clinical trial

Control group

1. Illiterate
2. persons who are accommodated in an institution on official or court order
3. persons in a dependent or employment relationship with the auditor
4. simultaneous participation in another clinical trial