The famous marshmallow test found that self-regulation in childhood can predict future success. The premise of the test is simple: You can eat one marshmallow now or, if you can wait, you get to eat two marshmallows later. The results were astonishing: the preschoolers who were able to wait for two marshmallows, over the course of their lives, have a lower BMI, lower rates of addiction, a lower divorce rate and higher SAT scores.
Similar studies have had success in linking personality traits to online behavior. Introverts disclose more information online than offline, but extroverts generally disclose more about themselves in either situation. Numerous studies have tested the effects of personality traits such as extraversion, neuroticism, and conscientiousness on technology use. The findings show that personality dimensions can predict the way individuals interact with digital technologies.

Recent research has found links between extrovert and narcissistic personalities and Internet use. However, these links are statistical correlations, and do not necessarily show causation. Correlations and causations tend to often get confused despite routine warnings in standard statistical texts. The most common illustration of this mix-up is the positive correlation between the number of storks nesting in a series of springs and the number of human babies born at that time.

Surprisingly, the correlation between the number of storks nesting and the number of human babies born does not prove the stork brings babies.

A very common mistake made by news media journalists—one has to believe it is quite often a deliberate mistake—is the interpretation of correlations as causations. I argue it is a deliberate mistake because it makes headlines sound more snappy: “Smartphones encourage narcissism”, “The Internet ‘Narcissism Epidemic’”, “The rise of the selfie and digital narcissism.” Such headlines and entire media reports are reinforcing the myth that technology causes narcissism, even though the studies many news reports rely on have found a correlation only.

Similarly, some journalists use data from long-term studies to claim that the current generation is more narcissistic than the generations before. But how do these studies link to increased use of web-based technologies? The answer is that they do not, but for those who are willing to believe technology is the cause of many downsides in our culture, it is easy to see proof of their suspicions. In reality, there are many other potential causes of higher narcissism levels, such as increases in general individualistic tendencies in Western societies over the last decades.

Indeed, the idea that individuals with personality traits like extraversion, neuroticism, or narcissism are more likely to engage in active use of social media technologies is much more evidence-based than the idea that social media causes these traits. If studies test narcissism levels of social media users and non-users, it is not surprising when they find higher levels among active social media users because previous research on personality traits supports the hypothesis that narcissistic personalities are more active social media users. But no study up to date has been able to prove that the stork (or in this case, technology) brings the babies (narcissism).