Raw data, analysis code, and full outputs are publicly available on the Open Science Framework (https://osf.io/9fqcm/). Analyses were conducted using R statistical software version 4.2.0, RStudio version 2022.2.2.485, and the packages dplyr 1.0.9 (Wickham, Francois, Henry, and Müller, 2022), tidyverse 1.3.1 (Wickham, 2019), kableExtra 1.3.4 (Zhu, 2021), psych 2.2.5 (Revelle, 2022), lubridate 1.8.0 (Spinu, Grolemund, and Whickman, 2021), jtools 2.2.0 (Long, 2022), sjPlot 2.8.10 (Lüdecke, 2021).
We used linear regression analyses to test for possible relationships between scores on the three subscales of the Three Doman Disgust Scale and estimated hormone levels. Each combination of disgust subscale (i.e., pathogen, sexual, or moral disgust) and method used to impute hormone levels (i.e., forward-counting or backward-counting method) were analyzed in separate models. In each model, disgust score was the outcome variable and estimated progesterone, estimated estradiol, their interaction, and participant age were predictors. All predictors were converted to z-scores prior to analyses. We included age as a covariate in light of previous research reporting age-related declines in pathogen disgust (e.g., Curtis et al., 2004). Model diagnostics (DFbetas and distribution of residuals) did not indicate any influential cases or deviation from the assumption of normality and homogeneity of residuals (see Field et al., 2012).
3.1.1. Pathogen disgust: For pathogen disgust, neither model showed any significant relationships. Results of these analyses are summarized in Table 2.
Table 2 Results of regression analyses when pathogen disgust was the outcome variable.
|
Estimates (std. Beta)
|
SE
(standardized)
|
t
|
P
|
95% CI
|
Model with backward-counting method (N = 1313)
|
Progesterone
|
0.06
|
0.05
|
1.20
|
0.229
|
-0.03 – 0.15
|
Estradiol
|
0.00
|
0.04
|
0.03
|
0.980
|
-0.08 – 0.09
|
Progesterone x Estradiol
|
-0.01
|
0.05
|
-0.27
|
0.786
|
-0.11 – 0.08
|
Age
|
-0.03
|
0.03
|
-0.93
|
0.354
|
-0.08 – 0.03
|
Model with forward-counting method (N = 1304)
|
Progesterone
|
0.04
|
0.03
|
1.28
|
0.200
|
-0.02 – 0.10
|
Estradiol
|
-0.04
|
0.03
|
-1.10
|
0.271
|
-0.10 – 0.03
|
Progesterone x Estradiol
|
-0.02
|
0.04
|
-0.49
|
0.624
|
-0.10 – 0.06
|
Age
|
-0.03
|
0.03
|
-1.15
|
0.251
|
-0.09 – 0.02
|
3.1.2. Sexual disgust: For sexual disgust, neither model showed any significant relationships for the hormone-level predictors, but both models showed significant negative relationships between participant age and sexual disgust. Results of these analyses are summarized in Table 3.
Table 3 Results of regression analyses when sexual disgust was the outcome variable.
|
Estimates (std. Beta)
|
SE
(standardized)
|
t
|
P
|
95% CI
|
Model with backward-counting method (N = 1313)
|
Progesterone
|
0.02
|
0.05
|
0.54
|
0.592
|
-0.07 – 0.11
|
Estradiol
|
-0.02
|
0.04
|
-0.53
|
0.599
|
-0.11 – 0.06
|
Progesterone x Estradiol
|
-0.05
|
0.05
|
-1.04
|
0.297
|
-0.14 – 0.04
|
Age
|
-0.14
|
0.03
|
-5.29
|
<0.001
|
-0.20 – -0.09
|
Model with forward-counting method (N = 1304)
|
Progesterone
|
0.00
|
0.03
|
0.08
|
0.937
|
-0.06 – 0.06
|
Estradiol
|
0.01
|
0.03
|
0.44
|
0.659
|
-0.05 – 0.08
|
Progesterone x Estradiol
|
-0.02
|
0.04
|
-0.38
|
0.705
|
-0.10 – 0.07
|
Age
|
-0.14
|
0.03
|
-4.96
|
<0.001
|
-0.19 – -0.08
|
3.1.3. Moral disgust: For moral disgust, neither model showed any significant relationships for the hormone-level predictors, but both models showed significant positive relationships between participant age and sexual disgust. Results of these analyses are summarized in Table 4.
Table 4 Results of regression analyses when moral disgust was the outcome variable.
Results of regression analyses when moral disgust was the outcome variable.
|
|
Estimates (std. Beta)
|
SE
(standardize)
|
t
|
P
|
95% CI
|
Model with backward-counting method (N = 1313)
|
Progesterone
|
-0.01
|
0.05
|
-0.27
|
0.788
|
-0.10 – 0.08
|
Estradiol
|
0.02
|
0.04
|
0.58
|
0.565
|
-0.06 – 0.11
|
Progesterone x Estradiol
|
0.01
|
0.05
|
0.16
|
0.877
|
-0.09 – 0.10
|
Age
|
0.17
|
0.03
|
6.27
|
<0.001
|
0.12 – 0.22
|
Model with forward-counting method (N = 1304)
|
Progesterone
|
0.04
|
0.03
|
1.25
|
0.211
|
-0.02 – 0.10
|
Estradiol
|
-0.00
|
0.03
|
-0.02
|
0.983
|
-0.07 – 0.06
|
Progesterone x Estradiol
|
-0.03
|
0.04
|
-0.75
|
0.451
|
-0.11 – 0.05
|
Age
|
0.17
|
0.03
|
6.17
|
<0.001
|
0.12 – 0.22
|
Repeating the analyses described above, this time with progesterone as the only predictor or with only progesterone and participant age as predictors, showed the same patterns of results (i.e., did not reveal any significant relationships between progesterone and disgust, see https://osf.io/9fqcm/ for full results of these analyses).
3.2. Robustness checks: We carried out further analyses (i.e., robustness checks) in which we repeated all of the analyses described above, this time including only (1) women for whom the number of days reported between the onsets of their last and next menses were between 20 and 35 days (1131 women met this criterion using the forward-counting method and 1131 women met this criterion using the backward- counting method) and (2) women for whom the number of days reported between the onsets of their last and next menses were between 25 and 35 days (1075 women met this criterion using the forward-counting method and 1075 women met this criterion using the backward-counting method). Again, none of these analyses revealed any significant effects of progesterone. Full results of these robustness- check analyses are available on the Open Science Framework (https://osf.io/9fqcm/).