Do hormones really determine our achievements: what actually influences motivation and success
Kyiv • UNN
Hormones and dopamine influence motivation, but they do not determine decisions or success. The environment, experience, skills, and opportunities are also important.
Hormones, brain function, heredity, and the external environment constantly influence how a person thinks, makes decisions, and acts. Because of this, it may seem that success or failure is predetermined by biology. However, the influence of hormones and neurochemistry is much more complex. Neuroscientist Vasyl Mykytiuk told UNN journalist more about the extent to which hormones actually influence our decisions, motivation, and ability to achieve goals, and whether brain chemistry and neurotransmitter levels can explain why some people are more persistent and successful while others give up more quickly.
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According to the neuroscientist, hormonal balance is indeed linked to motivation and behavior, but it is not a decisive factor, and the same hormone can act differently depending on the situation and a person’s existing predispositions.
Hormones influence decisions and motivation by increasing or decreasing the likelihood of behavior, rather than acting as a command. Stanford professor Robert Sapolsky puts it this way: testosterone does not create aggression; it amplifies existing predispositions in a particular context. Ultimately, hormones change the threshold for making decisions or initiating a particular behavior—how easily you take a risk, become angry, or give up. But they do not make decisions directly on your behalf
One of the best-known examples in discussions about hormones is testosterone. It is often associated with aggression, risky behavior, or the desire to dominate. However, studies, according to the expert, show a much weaker link than is often presented in popular explanations.
A meta-analysis by Geniole et al. (2020) debunks the popular myth about a correlation or causal relationship between baseline testosterone levels and aggression: baseline testosterone levels and aggression have a correlation coefficient of r = 0.054 (0.071 in men; 0.002 in women, meaning a very low interdependence)
This means that hormone levels alone cannot predict a person’s behavior. Other circumstances influence it, and sometimes a person’s own expectations about what is happening to them may play a significant role. This was demonstrated by another experiment involving testosterone.
The classic experiment by Eisenegger et al. in Nature (2010): women who received testosterone behaved more fairly in the “Ultimatum” game. Those who merely believed they had received testosterone behaved unfairly. The belief had a stronger effect than the hormone
When hormones can truly alter behavior significantly
Vasyl Mykytiuk notes that under normal physiological conditions, hormonal effects are often just one of many factors influencing behavior. They can become much more noticeable in certain physiological states.
Hormones truly play a decisive role primarily in extreme physiological or pathological states—hypothyroidism, Cushing’s syndrome, chronic stress involving prolonged exposure of the hippocampus and prefrontal cortex to glucocorticoids, sleep deprivation, or hunger. They also have a strong influence during puberty, pregnancy, and menopause
At the same time, such cases should not be generalized to all people without exception, the neuroscientist says. If the body remains within the physiological norm, hormones continue to influence behavior, but explain only part of the differences between people. This is important both for understanding motivation and for discussing achievement.
By contrast, within the physiological norm, hormonal effects on behavior do exist, but they usually explain only a minor portion of its variability
Why “successful brain chemistry” does not explain success
When discussing achievement, it is also important not to conflate hormones with neurotransmitters, the expert emphasizes. These are different systems of chemical communication in the body, although both may be associated with behavior. Dopamine, in particular, is involved in processes related to reward, motivation, and assessing how much effort a person is willing to exert.
The best-established role of the neurotransmitter dopamine is as an indicator of how much effort a person will make to achieve a goal. In a PET study, Treadway et al. (2012) found that dopamine release and sensitivity to it in such brain regions as the striatum and the ventromedial prefrontal cortex correlated with a willingness to exert more effort for a greater reward—especially when the chance of receiving the reward was low (12%). In other words, dopamine in these areas is associated with situations in which we work persistently to achieve success, even when the likelihood of such success is very low
In other words, the brain evaluates not only the possible outcome but also the price that will have to be paid for it. It is precisely the ratio of reward to costs that may influence whether a person is willing to exert more effort. At the same time, this does not mean that someone simply has the “right dopamine” and will therefore inevitably be successful.
Activity in the anterior insular cortex is inversely related: there, the “price or effort” we pay for this success is assessed. In general, the brain calculates the balance between the efforts we make and the motivation to achieve success
According to the expert, biological mechanisms help us understand how motivation arises. But between motivation and the actual result there are many intermediate stages. They are influenced by skills, living conditions, education, access to opportunities, the social environment, and other factors.
What is interesting is that in such pathological conditions as anhedonia in depression and apathy in Parkinsonism, the system of motivation and effort is disrupted. But it is a very long way from these explanations to the conclusion that “successful people have better chemistry” -
Therefore, biology may be part of the explanation for why a person is ready to exert more or less effort at a given moment. However, even a high level of motivation does not guarantee the desired result. Vasyl Mykytiuk explains that persistence can help, but it is not synonymous with effectiveness.
A meta-analysis of persistence (Credé et al., 2017; 88 studies, 66,807 participants): persistence does not mean effectiveness
Decisions are also influenced by external stimuli
A separate question is how strongly people can be influenced by things they do not even notice. These may include smells, words, temperature, context, or features of the environment.
Here, it is important to distinguish between two fundamentally different types of influence. On the one hand, there are long-term and cumulative environmental conditions: lack of sleep, hunger, chronic noise, air pollution, childhood exposure to lead, and poverty. Their consequences for cognitive functions, health, and behavior can be clearly observed in large samples. On the other hand, there are brief and often imperceptible stimuli: a smell, a word, the temperature on a particular day, or a slight change in the context of a choice. It was precisely regarding this second category that early psychological literature often reported extraordinarily large effects, which later turned out to be much more modest
In other words, a pleasant smell, for example, really can change one’s mood and certain consumer decisions, but the scale of this influence turned out to be relatively small. This is another example of how a popular explanation may prove to be considerably stronger than the actual effect.
A meta-analysis by Roschk and Hosseinpour (2020), covering 71 samples and 15,447 participants, showed that a pleasant ambient scent can indeed slightly improve mood and attitudes toward the environment and influence consumer behavior. But the scale of the effect is small: spending increased by approximately 3%, while time spent increased by approximately 5%." In other words, a smell can subtly nudge us, but this is more a slight shift in the probability of a behavior than “subconscious programming”
Why the environment is sometimes more important than willpower
Another important conclusion concerns self-control. The common idea is that a successful person simply has stronger willpower and is better at resisting temptations; however, current data encourage a more cautious approach to this explanation.
The theory of ego depletion proposed an intuitively appealing model: self-control is like a limited resource. If a person has already expended a great deal of "willpower," it should be harder for them to control themselves in the next task
Vasyl Mykytiuk explains that early experiments did indeed create the impression that the resource of self-control could be depleted. However, a larger replication produced a much weaker result. This means that the simple idea of a "willpower battery" does not explain human behavior as well as it once seemed to.
But in the large preregistered replication by Hagger et al. (2016), 23 laboratories and 2,141 participants carried out a standardized procedure. The resulting effect was only d ≈ 0.04 – practically zero. Subsequent studies produced mixed results. Therefore, the cautious conclusion is this: if the self-control depletion effect exists at all, it is probably much weaker and more context-dependent than the original theory predicted
So what does success ultimately depend on?
According to the neurobiologist, a person's achievements cannot be reduced to a single hormone, a single neurotransmitter, or an individual character trait. Biological processes establish certain conditions, but alongside them operate experience, environment, habits, opportunities, and specific decisions. It is precisely the combination of these factors that shapes behavior and influences the outcome.
Neurochemistry may explain the mechanism of persistence—how the brain evaluates rewards, costs, and effort—but by itself it does not explain who will ultimately achieve success
Thus, the popular formula about the "right hormones of a successful person" does not stand up to scrutiny. Hormones and brain chemistry are important for understanding motivation, but they are not a ready-made answer to the question of why some people achieve their goals while others do not. Success remains the result of the interaction between biology, experience, environment, and human behavior.
Acknowledging that a huge part of the causes of our behavior lies beyond our control does not mean acknowledging that our actions change nothing. On the contrary: if behavior depends on causes, it makes sense to look for causes that we can change. Therefore, the practical conclusion from this discussion is not "nothing depends on me," but rather: rely less on heroic willpower and instead design conditions in which the desired behavior becomes more likely—get enough sleep, reduce chronic stress, form habits, remove unnecessary temptations, plan actions in advance, and create an environment that works in your favor. And at the social level, the same principle leads to less certainty that successful people fully deserve their advantages, while failures fully deserve their failures. This is where Sapolsky's argument, regardless of whether we accept his conclusion about free will, becomes most practically significant