Hormones and the Coolidge effect

The Coolidge effect is the renewal of sexual behavior after the presentation of a novel sexual partner and possibly occurs as the result of habituation and dishabituation processes. This re-motivation to copulate is well studied in males and is commonly related to sexual satiety, which involves several neurobiological changes in steroid receptors and their mRNA expression in the CNS. On the other hand, there are few reports studying sexual novelty in females and have been limited to behavioral aspects. Here we report that the levels of rat proceptive behavior, a sign of sexual motivation, declines after 4 h of continuous mating, particularly in females that were unable to regulate the time of mating. Such reduction was not accompanied by changes in lordosis, suggesting that they were not due to the vanishing of the endocrine optimal milieu necessary for the expression of both components of sexual behavior in the female rat. These and previous data support important differences between sexual behavior in both sexes that would result in natural divergences in the Coolidge effect expression. We here also review some reports in humans showing peculiarities between the pattern of habituation and dishabituation in women and men. This is a growing research field that needs emphasis in female subjects.

Experimental Evidence for Sex Differences in Sexual Variety Preferences: Support for the Coolidge Effect in Humans

We examined sex differences in preferences for sexual variety and novelty to determine whether the Coolidge effect plays a role in human sexuality. In two experimental studies that employed different manipulations, we found converging evidence that men showed a greater preference for variety in potential short-term mates than did women. In the first study, men (n = 281) were more likely than women (n = 353) to select a variety of mates when given the opportunity to distribute chances to have sex with different individuals in hypothetical situations. This sex difference was evident regardless of the targets' attractiveness and age. Further, men found it more appealing if their committed romantic/sexual partners frequently changed their physical appearance, while women reported that they modified their physical appearance more frequently than did men, potentially appealing to male desires for novelty. In the second study, when participants were given a hypothetical dating task using photographs of potential short-term mates, men (n = 40) were more likely than women (n = 56) to select a novel person to date. Collectively, these findings lend support to the idea that sex differences in preferences for sexual variety and novelty are a salient sex-specific evolved component of the repertoire of human mating strategies.

Problematic pornography use and novel patterns of escalating use: A cross-sectional network analysis with two independent samples

Modern internet pornography allows users to harness sexual novelty in numerous ways, which can be used to overcome desensitisation through increasing volume of use (quantitative tolerance), progressing to more stimulating genres (qualitative escalation), skipping between stimuli (tab-jumping), delaying orgasm ('edging'), and engaging in pornographic binges. However, existing research has not yet evaluated how these potentially reciprocal consumption patterns relate to problematic pornography use (PPU). To this end, we recruited two independent samples of male pornography users (N1 = 1,356, Mage = 36.86, SD = 11.26; N2 = 944, Mage = 38.69, SD = 12.26) and examined the relationships between these behavioural dimensions and self-reported difficulties in controlling one's pornography use. Data were analysed through the network analysis approach (using Gaussian graphical models). As hypothesised, i) quantitative tolerance was centrally placed within the overall network, and ii) acted as a statistical bridge node between other patterns of pornography use (e.g., pornographic binges), and all measured facets of PPU. Our results are consistent with other emerging literature suggesting that tolerance, pornographic binges, tab-jumping, and edging behaviours as relevant features ofPPU, and that upscaling overall usage may connect broader patterns of use with problematic engagement. Clinical and theoretical implications, as well as future research directions, are discussed.