Why Doesn’t Everyone Respond the Same Way to the Same Stimuli?

Why do two people respond so differently to the same situation? Like why does one student perk up when a reward is offered, while another freezes at the possibility of getting something wrong? Why is feedback motivating for some and crushing to others? You completed an activity exploring these questions through two individual difference traits: sensitivity to punishment (SP) and sensitivity to reinforcement (SR).

What are the roots of exploring our sensitivities? Behaviorism. Behaviorists like B. F. Skinner taught us behavior comes from consequences. When something good happens after our behavior, we experience reinforcement and our behavior increases. We do it more! 😊 When something bad happens after our behavior, we experience punishment and our behavior decreases. We stop! ☹️

Years earlier, behaviorist John B. Watson famously claimed, “Give me a dozen healthy infants …” and he could train any of them to become a doctor, lawyer, artist purely through conditioning. Watson and Skinner, like most studying behaviorism, believed we are blank slates and life experience molds us.

Classic studies of instinctual drift show us animals, like us, aren’t quite blank slates. Animal trainers can condition extraordinary behaviors, like pigeons playing baseball and pigs grocery shopping! But the animals slowly drift back to their natural instincts, even if it meant losing rewards. We’re shaped by our experience, but we're also guided by temperaments and other aspects of our biology Individual differences inside two people conditioned exactly the same way, might respond totally differently because our brains respond to reinforcement and punishment in unique ways.

Sensitivity to Punishment (SP) reflects how strongly we respond to possible negative outcomes, like being corrected, getting in trouble, or doing something wrong. Everyone notices these things to some extent, but people differ in how much they react emotionally and behaviorally to punishing consequences. Your score can give you insight into whether you lean toward caution, conflict avoidance, or heightened emotional responses to mistakes (table 1)

Women tend to score a little higher in SP than men (Fullana & Torrubia, 2003; Matton et al., 2013). For example, in our sample the middle 50% of women scores 43 to 70 and the middle 50% of men scores 34 to 64. Like nearly every psychological gender difference, there's a lot of overlap.

My SP score is 75. I tend to over-prepare and feel uncomfortable when I think I might get something wrong. Letting go of perfectionism is something I work on. But I realize sensitivity can be a strength too. It helps me tune in and care deeply.

Sensitivity to Punishment and Mental Health
A lot of research about SP considers our mental health. Higher SP is associated with:

• Anxiety and OCD (Fullana et al., 2004; Bijttebier et al., 2009)
• Depression (Guimón et al., 2007; Bijttebier et al., 2009)
• Eating disorders like anorexia and emotional eating (Matton et al., 2013; Jappe et al., 2011)
• Greater startle and physiological response to negative images (Aluja et al., 2015; De Pascalis et al., 2005)

People high in SP experience more stress, sadness, or shame (Fullana & Torrubia, 2003; O’Connor et al., 2004). They tend to be a bit more neurotic and introverted (Torrubia et al., 2001; Fullana & Torrubia, 2003).

Please remember higher SP is linked with positive qualities too, like: greater caution, deeper empathy, and planning thoughtfully.

🪞Moment of Reflection!
How do you respond to pressure or possible mistakes? Does your SP score match your experience?

Sensitivity to Reinforcement (SR) reflects how strongly we respond to positive outcomes, like praise, success, recognition, or winning something. Some people are wired to chase rewards; others are less swayed by external incentives. Your score helps you understand what motivates you—and what might not (table 2).

Men tend to score a little higher in SR than women (Fullana & Torrubia, 2003; Matton et al., 2013). For example, in our sample the middle 50% of women scores 34 to 57 and the middle 50% of men scores 39 to 63. Like nearly every psychological gender difference, there's a lot of overlap.

My SP score is 37.5. I tend to stay steady regardless of external rewards, and I’m more guided by meaning and values than praise or prizes.

Sensitivity to Reinforcement and Mental Health
A lot of research about SR considers our mental health. Higher SR is associated with:

• Bipolar symptoms and impulsivity (Bijttebier et al., 2009; Torrubia et al., 2001)
• Bulimia and binge eating (Matton et al., 2013)
• Substance use and behavioral addictions (Lyvers et al., 2016; Vargas et al., 2019)
• Stronger physiological response to positive stimuli (Aluja et al., 2015)

People high in SR tend to have more emotionally high highs and low lows (Fullana & Torrubia, 2003; O’Connor et al., 2004). They tend to be a bit more impulsive and extraverted (Torrubia et al., 2001).

But please remember higher SR is linked with positive qualities too, like: greater enthusiasm, social drive, and sensation-seeking.

🪞Moment of Reflection!
What tends to motivate you? Does your score match how you respond to praise, rewards, or competition?

Your scores don’t define who you are. They give you a lens, a way of reflecting on what moves you, what challenges you, and how your brain might be wired. Let your scores spark curiosity, not conclusions.

Even when a score feels meaningful, the full picture is often more complex. For example, students with ADHD may not respond to reinforcement in the same way every time - not because they’re unmotivated, but because their brains process reward and effort differently (Kofler et al., 2016). Some need rewards to be more immediate. Others need tasks to feel personally relevant or emotionally engaging.

Sensitivity to punishment and reward isn't about being strong or weak, lazy or driven. It's about how your minds filter the world. We can be active learning ways to filter the world differently, like self-talk when we're perfectionistic. And we can learn to work with our patterns, instead of against them.

Whether you felt seen in your results or confused by them, I hope you walk away knowing this. You are more than your scores. You are worth understanding. And the more you reflect, the more you grow.

Uneasy Feelings about Your Results?
Please remember your results with any activity are not who you are. Your results are a 'snapshot' of a moment when you did an activity. It's just one measure, a single thread, of the many strands of who you are. Any result is a guess with statistical error. And it's possible the measure is flawed in a way so it doesn't work for you. Please do not think of your results as definitive dogma. Instead they're a starting point for our self reflection. Please keep in mind too, self-reflection can feel uncomfortable. "Bad" feelings are not actually bad. They're information. So, even if your activity result is inaccurate and flawed, you might ask yourself what your feeling is trying to tell you? Trusted teachers, friends, and therapists can be helpful. I wrote an essay elaborating with concrete examples how we can appreciate uneasy feelings about our activity results.

Scholarly Information?
You're welcome to use Copernican Revolution activities and essays for your thesis and studies. Having information about scholarly aspects like psychometric data, activity design details, and norm calculations may help. The primary focus of my essays is connecting educated laypersons with psychology. To help people like you, with advanced academic interests, I add an appendix with each activity.

Kofler, M. J., Rapport, M. D., Bolden, J., Sarver, D. E., & Raiker, J. S. (2016). ADHD and working memory: The impact of central executive deficits and exceeding storage/rehearsal capacity on observed inattentive behavior. Journal of Abnormal Child Psychology, 44(1), 195–210.

Torrubia, R., Avila, C., Moltó, J., & Caseras, X. (2001). The sensitivity to punishment and sensitivity to reward questionnaire (SPSRQ) as a measure of Gray’s anxiety and impulsivity dimensions. Personality and Individual Differences, 31(6), 837–862.

Bijttebier, P., Beck, I., Claes, L., & Vandereycken, W. (2009). Gray's Reinforcement Sensitivity Theory as a framework for research on personality–psychopathology associations. Clinical Psychology Review, 29(5), 421–430.

Fullana, M. A., & Torrubia, R. (2003). Personality and declarative memory: disentangling the role of arousal and attentional resources. Personality and Individual Differences, 34, 1343–1351.

Matton, A., Goossens, L., Braet, C., & Vanhalst, J. (2013). Punishment and reward sensitivity: Associations with disordered eating behaviours. European Eating Disorders Review, 21(4), 259–265.

Aluja, A., García, O., & García, L. F. (2015). Startle response modulation and personality: A psychophysiological study. Biological Psychology, 106, 11–19.

Lyvers, M., et al. (2016). Sensitivity to punishment and reward and internet addiction. Addictive Behaviors, 64, 92–98.

Jappe, L. M., et al. (2011). The role of punishment and reward sensitivity in eating disorders. European Eating Disorders Review, 19(2), 87–97.

Guimón, J., et al. (2007). The role of sensitivity to punishment and reward in major depressive disorder. Journal of Affective Disorders, 104(1–3), 241–246.

Morillo, D., et al. (2020). Frustration intolerance and sensitivity to reinforcement. Journal of Contextual Behavioral Science, 15, 52–58.