Measuring female intrasexual competition by the scale for intrasexual competition: a validation of the German version

Abstract

Competitive behaviour amongst members of the same sex is termed intrasexual competition. The tendency to engage in such competition appears to be strongly related to stable individual characteristics such as personality traits. Additionally, recent studies have revealed transient fluctuations in competitiveness according to the female menstrual cycle. To date, no German questionnaire exists to measure intrasexual competition. Our first study aimed to translate and validate the Intrasexual Competition Scale (ICS) by Buunk and Fisher (J Evol Psychol 7:37-48, 2009) in a population of healthy Swiss females (n = 241). Our second study applied the validated German ICS in a group of healthy, regularly cycling females (n = 49) in order to examine possible associations between the menstrual cycle phase and ICS scores. The psychometric properties suggest that the German ICS is a reliable and valid tool to assess individual differences in female intrasexual competition. Furthermore, our second study demonstrated that on average, women showed higher intrasexual competition scores when tested in the late follicular phase (M = 35.77 ± SD = 12.03) compared to the mid-luteal phase (M = 30.93 ± SD = 10.20). Our studies support previous findings of an association between ICS scores and relatively stable individual characteristics such as personality traits. Furthermore, our research endorses the assumption of cycle-dependent fluctuations in intrasexual competition. Future research should clarify the precise mechanisms underlying these findings and include biomarkers such as oestrogen and testosterone.

Female Intrasexual Competition and Its Link to Menopausal Stage, Sex Hormone Levels, and Personality Characteristics

“…The validated German version of Buunk and Fisher's ( 5 ) Scale for Intrasexual Competition was applied ( 5 , 6 ). The questionnaire consists of 12 items which are rated on a 7-point Likert scale ranging from ( 1 ) not at all applicable to ( 7 ) completely applicable (i.e., “I can't stand it when I meet another woman who is more attractive than I am.” “I tend to look for negative characteristics in attractive women.”).…”

“…The Cronbach's alpha in this study was 0.86, suggesting a good internal consistency. As proposed in our validation study, subscales were calculated for the competition on (I) attention and interpersonal success, (II) competence, and (III) appearance ( 6 ). Cronbach's alphas for these subscales were 0.80 for attention and interpersonal success, 0.79 for competence, and 0.75 for appearance.…”

“…Previous research suggests that female ISC is influenced by psychosocial and physiological, particularly endocrinological, factors. Studies have shown more pronounced ISC in young or midlife women with certain personality characteristics, including those who are less agreeable ( 4 , 5 ), less extraverted, less conscientious ( 6 ), or higher in neuroticism ( 4 , 6 ); findings for self-esteem are mixed ( 7 , 8 ). Such findings indicate a trait-like component of ISC, explaining why certain women compete more than others.…”

“…Such findings indicate a trait-like component of ISC, explaining why certain women compete more than others. There is additional evidence that ISC fluctuates within a woman, potentially paralleled by the changing sex hormone environment across the menstrual cycle ( 6 , 9 ). Framed according to the ovulatory competition hypothesis , the assumption is that ISC is more likely to translate into reproductive success when applied closer to ovulation ( 10 ).…”

Cultural dimensions associated with intrasexual competitiveness.

“…First, ISC has been found to be associated with hormones. For example, among women ISC is higher during the late follicular phase compared to the midluteal phase of the cycle (Fiacco et al, 2018), and among men ISC is higher among those high in testosterone (Arnocky et al, 2018). Furthermore, Buunk et al (2014) found that young women were consistently higher in ISC the higher the socioeconomic status of their parents, assumedly because young women are currently on average more highly educated than young men are, intensifying female competition over highly educated men.…”