The study recruited 128 participants, evenly split between 64 men and 64 women, and assigned each of them to one of three experimental conditions. In the first, known as the pleasant affective induction, participants viewed a series of images chosen to evoke positive feelings. In the second, the neutral affective induction, the images were deliberately unremarkable. In the third, the unpleasant affective induction, the pictures were selected to stir negative emotions. The images came from the International Affective Picture System, a standardized and extensively validated library of photographs rated for emotional valence and arousal, which has been adapted for Spanish-speaking populations by several research groups over the past two decades. This standardization matters: it means the emotional pull of each image is not guesswork but a quantified property, allowing experimenters to induce affective states with reasonable confidence that participants across conditions experienced genuinely different moods.

To verify that the inductions actually worked, the researchers administered the Positive and Negative Affect Scale, or PANAS, before and after the experimental session. This widely used instrument asks participants to rate the extent to which they are currently experiencing a range of feelings, from enthusiastic and inspired to distressed and jittery, yielding separate scores for positive and negative affect. The results confirmed that the manipulations shifted participants’ emotional states in the expected directions, with pleasant images raising positive affect and unpleasant images raising negative affect. The authors are careful to note, however, that the before-and-after measurements reflect a compound effect: they capture not only the influence of the images themselves but also the experience of completing the decision-making task that sat between the two assessments. Disentangling those two contributions is a persistent challenge in this line of research, and the study’s design acknowledges it openly.

The heart of the experiment was the Iowa Gambling Task, a legendary instrument in the psychology of decision-making. Developed in the 1990s by Antoine Bechara, Antonio Damasio, and colleagues to study patients with damage to the prefrontal cortex, the task presents participants with four decks of cards. Each card draw yields a monetary gain or loss, but the decks differ in their underlying payoff structures. Two decks are advantageous over the long run, offering modest rewards with occasional small penalties, while the other two are disastrous, dangling large rewards that are ultimately swamped by punishing losses. Healthy participants gradually learn to favor the good decks, often before they can articulate why, a phenomenon that helped inspire Damasio’s famous somatic marker hypothesis: the idea that emotional signals from the body guide our choices, and that decision-making without emotion is not purer reasoning but impaired reasoning.

Because the task’s rules are never explained, performance on the Iowa Gambling Task is typically decomposed into two phases. Early draws are considered decisions under conditions of ambiguity, when participants cannot yet know the consequences of their choices. Later draws, once the payoff structure has implicitly been learned, are treated as decisions under risk. This distinction is more than a technicality. Research by Brand, Recknor, Grabenhorst, and Bechara has shown that the two phases correlate with different cognitive abilities, with decisions under risk engaging executive functions and explicit knowledge to a greater degree. The Spanish team analyzed performance across both phases, and their statistical power analyses indicated the design was sensitive enough to detect even moderate interaction effects, with power reaching 0.92 for the decisions-under-risk model.

The headline finding is strikingly asymmetric. Men who had been shown pleasant images scored significantly higher on the task than both women in the same pleasant condition and men in the neutral and unpleasant conditions. In other words, positive affect acted as a performance enhancer, but only for male participants. Women’s scores, by contrast, remained stable across all three affective inductions. Whatever mood the images stirred up, their decision-making on the gambling task did not budge. The researchers interpret this pattern as evidence that men are more susceptible to the facilitative influence of positive affect, which appears to improve their decision-making performance, while women exhibit greater behavioral stability, suggesting their decision-making processes are less vulnerable to affective fluctuations.

Why might this be? The authors situate their findings within a rich theoretical landscape. Barbara Fredrickson’s broaden-and-build theory holds that positive emotions expand the scope of attention and cognition, encouraging exploration and flexible thinking, which could plausibly help a participant learn the hidden structure of a gambling task faster. If that mechanism operates more strongly in men, perhaps due to differences in how emotions interact with reward circuitry, the advantage becomes explicable. Hormonal evidence offers another thread: studies have linked testosterone to risk-taking on the Iowa Gambling Task specifically, and neuroimaging work has connected testosterone to activity in the orbitofrontal cortex, a region central to the somatic marker framework. Meanwhile, the stability observed in women resonates with a substantial literature on sex differences in emotion regulation. Research by McRae, Ochsner, and Gross has shown that men and women recruit overlapping but not identical neural machinery when reappraising negative images, and work on emotion regulation flexibility suggests women may deploy a broader repertoire of strategies with greater context sensitivity, potentially buffering their cognition from mood swings.

The new study also converges with, and helps to refine, a growing body of work on sex differences in the Iowa Gambling Task itself. A 2024 meta-analysis by Zanini, Picano, and Spitoni in Neuropsychology Review confirmed that men and women perform differently on the task as a rule, but the sources of that difference have remained contested. Earlier findings complicated the picture further: a 2019 study by Flores-Torres and colleagues found that induced humor improved women’s performance on the task while impairing men’s, the opposite direction of the present results for positive affect. Such contradictions underscore that affect is not a single lever. Different positive states, induced by different means, may act through different pathways, and the current study’s use of standardized affective images rather than humor provides one specific and reproducible route to the effect. What both studies share is the conclusion that sex cannot be treated as a statistical nuisance variable; it moderates how emotion and cognition interact.

The practical implications stretch well beyond the laboratory. Decision-making performance on tasks like the Iowa Gambling Task has been linked to real-world outcomes ranging from relapse in stimulant dependence to financial choices and clinical conditions such as major depressive disorder. If mood shifts translate into better or worse decisions differently across sexes, then contexts that manipulate emotion, from high-pressure workplaces to trading floors to therapeutic settings, may affect men’s and women’s choices in systematically different ways. The findings also carry methodological weight for researchers: experiments that induce moods before measuring cognition should analyze sex as a moderating variable, not merely control for it, or they risk averaging away effects that are real but opposite or absent in half their sample.

The authors are candid about their study’s limits. The sample was recruited by convenience rather than by an a priori power analysis, though subsequent sensitivity analyses showed the design could reliably detect effect sizes of a moderate magnitude. The PANAS measurements cannot fully separate the effect of the mood induction from the experience of the task itself, and the study examines a single moment in time rather than tracking how durable these mood effects might be. The dataset has been made publicly available in Mendeley Data, inviting other researchers to probe the patterns independently. Still, the core message stands with unusual clarity: emotion does not act on decision-making uniformly across people. A lift in spirits may open the doors of opportunity for some minds while leaving others untouched, and understanding why may require looking not just at the brain’s emotional circuitry, but at how that circuitry is wired differently across the population. In the ongoing effort to map the tangled relationship between feeling and thinking, sex has now earned its place as a critical variable, one that future models of affective decision-making ignore at their peril.

Subject of Research: Sex differences in how induced affective states influence decision-making performance on the Iowa Gambling Task

Article Title: Sex differences in the influence of affective state on decision-making

Article References: Sex differences in the influence of affective state on decision-making. (n.d.). https://doi.org/10.1007/s12144-026-10152-2

Image Credits: AI Generated

DOI: 10.1007/s12144-026-10152-2

Keywords: decision-making, Iowa Gambling Task, sex differences, affective state, emotion regulation, positive affect, PANAS, somatic marker hypothesis, prefrontal cortex, risk-taking, Current Psychology, mood induction