How Well Do People Know Themselves

Research Team Explores the Phenomenon of Self-knowledge

In a comprehensive study, an international research team led by Max Planck researcher Isabel Thielmann has concluded that self-knowledge—that is, the accurate perception of one’s own personality traits and momentary states—is not a general, universal skill, but rather context-dependent and changeable. The study, published in the journal Nature Reviews Psychology, synthesizes existing research and represents a major step toward scientific consensus. 

How accurately do we perceive ourselves? In a new study, an international team of researchers is shedding light on this question—one that has occupied philosophers and psychologists for centuries. What is self-knowledge? How can it be measured? Is more of it always a good thing? And can self-knowlege change? These are the key questions the research team is exploring.

The study aimed to formulate and debate hypotheses based on existing research—and ultimately to reach a scientific consensus. To achieve this goal, Isabel Thielmann and her Max Planck team are using the so-called Delphi method. This scientific method is a structured, multi-stage survey process in which experts are questioned on key issues within a field of research with the goal of reaching a consensus. For this study, 17 qualified psychologists were surveyed on the topic of self-knowledge.

Self-knowledge was defined as follows: Self-knowledge describes the extent to which a person has accurate perceptions of their own relatively stable characteristics and momentary states (e.g., personality features, abilities, affect, motivations, preferences, physical appearance, behaviors).

The experts agreed on the conclusions below, but at the same time emphasize that there is a lack of empirical evidence in some areas. This is partly because measuring self-knowledge is challenging. According to the researchers, self-knowledge is typically measured by comparing self-perception with an external, reliable criterion, such as observations by friends or colleagues, or through performance tests.

1. Self-knowledge is domain-specific

Just because someone can accurately assess their math skills doesn’t mean they automatically know how they will react in emotionally charged situations. Self-knowledge is domain-specific—it can be strong in one area but absent in another. There is no such thing as a single, universal form of self-knowledge.

2. Greater self-knowledge isn’t always a good thing

Greater self-knowledge isn’t necessarily always better. Scientists unanimously agree that being aware of one’s own weaknesses or undesirable traits can be stressful. People who become too acutely aware that they are impulsive or unreliable may experience psychological distress as a result—and may even consciously avoid certain information.

This is why the idea of “positive illusions”—that is, a slightly distorted but positive self-perception—is not only popular but also psychologically plausible. In some situations, a slightly more optimistic view of oneself can even be healthier than an entirely accurate one.

Often, however, it can indeed be important to be able to assess oneself realistically, for example, when it comes to choosing the right job. “Generally speaking, it is beneficial for people to be able to accurately gauge their relative strengths and weaknesses. This helps, for example, with many decision-making processes,” explains study director Isabel Thielmann.

3. Self-knowledge can be changed, but it’s not easy

Self-knowledge is malleable. It can grow through new information—such as constructive feedback, reflection, or life experiences. It can also improve through conscious self-exploration or therapy. Improving self-knowledge requires insight, courage, openness, and targeted strategies.

“With our study, we set out to systematically consolidate existing knowledge in the field of self-knowledge, to compile the current state of research, and in doing so, to lay the groundwork for a scientific consensus,” Isabel Thielmann summarizes. “However, the study can also provide valuable impetus for anyone who wants to better understand themselves.”

The study was conducted as part of the EU-funded project KNOW-THYSELF. Learn more about the project here.