Women’s obligatory parental investment may lead women to value men’s ability and willingness to invest in future offspring when evaluating long-term mates. Although men’s disposition toward parental investment has received less attention than their resource acquisition ability, several studies have shown that behavioral cues to men’s willingness to invest influence women’s evaluations. However, it remains unclear whether parental investment cues specifically influence long-term mate attractiveness or generally increase favorability. This study used text-based profiles to examine whether cues to men’s willingness to invest have domain-specific effects on women’s evaluations. Female nursing school students in Japan (N = 254) were randomly assigned to read a male profile that either included or did not include parental investment cues and then evaluated the target man across long-term mating, short-term mating, and non-mating contexts. The results showed that men described as having positive attitudes toward parenting and children were evaluated as more attractive as long-term mates, but less attractive as short-term mates. No effects were observed for non-mating evaluations, namely friend attractiveness and general liking. These findings suggest that men’s attitudes toward parenting and children serve as cues to men’s willingness to invest in future offspring and influence women’s evaluations in a domain-specific manner. The study findings also suggest that parental investment cues may signal not only men’s suitability as long-term mates but also their lower suitability as short-term mates. This study provides evidence for the domain specificity of parental investment cues and highlights the importance of such cues in human mate choice.
Did the Black Death coincide with a change in genetic variants linked to educational attainment in Europe? We analysed educational-attainment polygenic scores in ancient European genomes. Among 4,941 individuals, the score’s trajectory became more positive after 1350 CE. The estimated change in slope was 0.046 standard deviations per century in the weighted model (population-clustered p = 0.005), although the unweighted model gave weaker evidence (p = 0.077). In a separate comparison of 754 medieval individuals, adjusted scores were higher in those dated to 1350–1599 CE than in those dated to 1000–1349 CE (difference = 0.142 SDs; p < 0.001). Higher estimated local Black Death mortality was also associated with a stronger post-1350 change in the score’s trajectory, both using numerical mortality estimates alone and when qualitative historical estimates were included (p < 0.001 in each analysis). Uneven sampling, incomplete locality matching and uncertain mortality estimates limit causal interpretation.
If the democratic peace explains the avoidance of interstate wars, what (besides the absence of democracy) explains their occurrence? Theoretical developments in evolutionary psychology suggest that nations with higher average intelligence may be more likely to resort to interstate wars as a means of resolving international conflict, but that national IQ has no effect on the occurrence of civil wars. This is because civil wars are evolutionarily familiar while interstate wars are evolutionarily novel. The analyses of the Correlates of War data confirm these predictions, and show that, net of economic development, democracy, and world-system status, national IQ has a significantly positive effect on the frequency and scope of interstate wars, but has no effect on the frequency and scope of civil wars. The positive effect of national IQ on interstate wars is larger and more consistent than the negative effect of democracy. Thus intelligent belligerence appears to be a more robust principle in international relations than democratic peace.
Suicidology has achieved little explanatory or preventive progress despite decades of intensive research. This article argues that the stagnation stems from a problematic but undeclared paradigm: that Suicide Overrides Superordinate Impetus for Survival (“SOSIS”). Across the field, suicide is routinely framed as defying a presumed instinct for self-preservation or some such life tendency—and, therefore, scientifically puzzling. Drawing on historical and contemporary sources, this review shows that SOSIS has functioned as a disciplinary axiom and a conceptual prior but is rarely interrogated. Despite appearing a bioscientific principle, SOSIS is epistemically unfounded: the notion of a survival instinct collapses into tautology; the assumption that suicide entails its override constitutes circular reasoning; and teleological appeals to survival as evolution’s “goal” misrepresent Darwinian principles. The outlook is traced to, not bioscience, but a metaphysical, fundamentally extra-scientific intuition. The paradigm has channeled inquiry into fruitless searches for special predictors and suicidogenic mechanisms, while insulating the field from potentially useful inputs from mainstream life sciences. It generates a proliferation of derivative theories, without resolution, and inserts a prescriptive agenda into scientific discourse under the guise of descriptive inquiry. With SOSIS here identified as a contingent paradigm, rather than a biological truth, space opens for reorientation. A contrasting framework interprets suicidal behavior not as an aberrant breach of human nature but as an emergent outcome of a complex, evolved system. Progress in suicide science requires recognizing that the SOSIS paradigm operates, realigning conceptual foundations with evolutionary biology, and considering models that better explain human self-destructive behavior.
Despite decades of research, no consensus has emerged regarding why music evolved in humans. Existing evolutionary accounts—including sexual selection, social bonding, parent–infant communication, group coordination, emotional regulation and cognitive by-products—have generated substantial empirical support, yet they are typically presented as competing explanations. This competitive framing has obscured the possibility that these hypotheses describe complementary functions operating within a higher-order adaptive organization rather than mutually exclusive evolutionary scenarios. Here we argue that the current debate is constrained by the absence of an organizational level of explanation capable of integrating these diverse functional contributions into a coherent evolutionary framework. We propose an organizational perspective in which music is understood as an adaptive system that coordinates multiple cognitive, affective and social processes across different temporal and behavioural scales. Within this perspective, we develop the Adaptive Cognitive Tool hypothesis as one empirically testable interpretation. Rather than attributing musical evolution to a single selective pressure, this hypothesis proposes that music enhanced human adaptive capacity by dynamically organizing attention, prediction, memory, emotional regulation, motor synchronization and social coordination, thereby improving behavioural flexibility in complex and changing environments. This perspective generates testable predictions, reconciles apparently conflicting evolutionary hypotheses and suggests that the remarkable universality and multifunctionality of music are expected consequences of its integrative organizational role. More broadly, it illustrates how organizational explanations may complement traditional adaptationist approaches in understanding the evolution of complex human behaviours.
