Research Themes

Integrating philosophy and science

My research focuses on human flourishing, encompassing topics like happiness, well-being, and meaning in life. My approach these topics crosses traditional disciplinary boundaries, integrating methods from philosophy and psychology. For instance, I have advocated for perfectionism as a philosophical theory of well-being and defended a philosophical analysis of the idea that life has "meaning". I have also empirically investigated the ordinary concept of a meaningful life, how people form judgments about whether someone is happy, as well as the causes of happiness, a sense of meaning in life, and other aspects of well-being.

I believe that an interdisciplinary approach is important because claims about human flourishing and well-being involve both empirical assertions and value judgments. I’ve also argued that scientific research on human well-being would benefit from more, and more public and inclusive, discussion of the values that shape and direct this research. Conversely, because the plausibility of philosophical theories of well-being depends on assumptions about what humans are like, empirical investigation is equally important for philosophical theorizing.

Fortunately, it seems that philosophical work on well-being is increasingly empirically-engaged. In a bibliometric analysis, I found that papers in the philosophy of happiness and well-being are citing scientific sources increasingly often. In fact, papers in this area that don't cite scientific sources are now a minority.

Life's meaning

One of the things that makes meaning in life a difficult topic for rigorous study is the many and varied ways in which people talk about life having “meaning.” I have argued that understanding can be gained from the idea that meanings (in general) are learned through correct interpretation. Interpretation, on my view, is a “sense-making” process, involving fitting something coherently into a web of background knowledge. Thus, seeing meaning in life requires interpreting life. The many ways that people talk about life’s meaning therefore reflect different things that “life” can refer to and different contexts into which life can be situated.

Even if we can make sense of the idea that life has, or can have, meaning, it remains unclear what exactly would make a particular person's life meaningful. Philosophers have proposed three answers to this question. Yet, in my research, I have found that none of these theories reflects the way that people ordinarily think. Instead, most people appear to see mental states and subject-independent value as making independent and additive contributions to the meaning in a person’s life. (Check out this video for more about the standard views and my experiments.)

One of the findings from these experiments is that people see immorality as incompatible with living a meaningful life. However, there is reason to believe that the relationship between morality and meaningfulness is far more complicated. For instance, in a recent study, I found that most people do not consider extremely immoral lives meaningless (e.g., Stalin's life). In an ongoing project, I am investigating this issue further.

(How) do we matter?

What leads a person to think that they matter? In a recent paper, my colleagues and I differentiated between several forms of perceived mattering. People can think that they matter to others, whether people in general, or family and friends specifically. People can also think that they matter in their community or society. And they can think that they matter in the grand scheme of the universe. We found that each of these forms of perceived mattering displays a unique pattern of association with personality traits and mental health outcomes. For instance, whereas perceived cosmic mattering and societal mattering were each independently associated with narcissism, perceived mattering to close others was not. In contrast, whereas perceived mattering to close others and to one’s society were associated with suicidal ideation, perceived cosmic mattering was not. In an ongoing project, I am investigating how demographics (e.g., race, gender, age) and structural factors (e.g., income inequality, crime rates) affect an individual's sense that they matter.


This distinction between the various forms of perceived mattering turns out to be important for answering other, related questions. My collaborators and I recently investigated why religiousness is associated with a sense of meaning in life. One popular hypothesis is that this link is explained by social factors: feelings of belonging and interpersonal significance that can come from membership in a religious community. However, our results suggested that a sense of interpersonal significance was only a small part of the explanation. Instead, the primary reason why religiousness is associated with perceived meaning in life is because it fosters a sense of cosmic significance. That is, the more a person is religious, the more they tend to feel that they matter, even in grand scheme of the universe. This sense of cosmic significance, in turn, supports their sense of meaning in life.

The idea that a person could matter in the grand scheme of the universe might seem odd, at least to those who are not religious. After all, the observable universe is incomprehensibly vast. Against that background, does any human being really matter? And should this matter to us whether we do? In the experiment reported in this video, I found that prompting people to reflect on the enormity of the universe reduced their sense of significance and meaning in life. Yet, though some people responded negatively to such reflection, others responded positively. Recognizing humanity's cosmic insignificance can feel threatening. But it can also feel consoling.

Individual and planetary well-being

Mitigating climate change is one of the most serious challenges facing humanity today, and will require action at many levels: governmental, corporate, and individual. I believe that one of the major hurdles to widespread behavior change is the mistaken belief that pro-environmental behaviors are self-sacrificial. To the contrary, sustainable behaviors and lifestyles are generally good for a person’s well-being. For example, physically active modes of transportation (like walking or biking versus driving) reduce emissions and improve physical and mental health. Living with other people reduces per person household energy use and often typically leads to greater social support. Lower-emissions diets (i.e., those low in animal products and processed foods, and high in fruits and vegetables) are generally healthier than higher-emissions diets. Although there are bound to be plenty of exceptions to this generalization, there seem to be many "win-wins" for individual and planetary well-being.

Hence, I have argued that we need to change the way that we think and communicate about sustainable behavior. Focusing on personal benefits of sustainability could be a powerful motivational tool. Indeed, in a pair of experiments, I found that well-being messages—i.e., messages about how going green can be good for you—improved attitudes towards, and strengthened intentions to engage in, pro-environmental behavior. In the second of these experiments, I also found that when people learn about the potential personal benefits of sustainability, it doesn't just affect them. It also affects the people they subsequently interact with. These “ripple effects” could begin to reshape social norms, and perhaps prompt more vigorous climate action.

Although there is now a large body of evidence that pro-environmental behavior is positively correlated with happiness, experimental evidence is needed to establish causation. I am currently running such an experiment. Preliminary results should be available soon.

The importance of co-experienced positive emotion

Interpersonal connection is vital to individual and societal flourishing. My colleagues and I have found that moments of positive social connection are vital to a person’s mental health and sense of meaning in life. In a longitudinal experiment we found that instructing people to create more of these moments led to increases in prosociality (e.g., altruism, humility, and a sense of connection to all life). We've even found that these moments of interpersonal connection led to greater compliance with pandemic-era public mandates (e.g., social distancing and mask requirements). In contrast, we’ve found that technologically mediated interactions on social media can have the opposite effects.


In an ongoing project, my colleagues and I are testing whether artificial intelligences that have been designed to emulate high-quality conversation partners could encourage people to seek out more human-to-human connection. Many researchers have expressed grave concerns about how AI will affect humanity, in both the immediate and more distant future. However, this research suggests, as I have elsewhere argued, that it may be possible to design AI systems in ways that support human flourishing.

Moral influences on emotion attributions

Imagine a nurse who is in a good mood most of the time and is quite satisfied with her life. Now suppose you learn that she has been poisoning her patients. Do you think she is happy? Empirical studies have found that people consider immoral agents less happy than moral agents—independently of how their psychological states are described. This fits with a view, defended by some philosophers, that the concept of happiness includes a role for normative considerations. That is, a person is not truly happy unless their happiness is fitting. However, I have proposed an alternative explanation, according to which people typically believe that the "true self" (i.e., who a person really is deep down) is morally good. For this reason, people typically see immoral behavior as a source of intrapersonal conflict, which impedes happiness.


In a series of experiments, I found that immoral agents are typically seen as highly conflicted. But when they are plausibly described as not being conflicted, people think they are just as happy as moral agents. One difficulty for pitting the fittingness hypothesis against my true self hypothesis is that, when it comes to happiness, judgments about fittingness and the true self are difficult to pry apart. That is, the same thing that makes happiness unfitting might be seen to make it less reflective of a person's true self. Hence, in another series of experiments, my collaborators and I recently compared the implications of the fittingness hypothesis and the true self hypothesis across a range of emotions: happiness, love, sadness, and hatred. Our thought was that, for these other emotions, judgments about fittingness and the true self would not be so entangled. This assumption proved to be correct. Crucially, we found that manipulating the fittingness of an agent’s emotion affected emotion attributions only when it also affected true self judgments. However, manipulating whether an agent’s emotion reflects their true self affects attributions of all four of these emotions, regardless of the effects on fittingness judgments.


Overall, then, my research suggests that normative considerations are not built into the concept of happiness. Instead, the intuitions about happiness are influenced by normative considerations when and because people believe in the inherent goodness of human nature.