In 2011, Yale law professor Amy Chua became a household name after publishing her book Battle Hymn of the Tiger Mother, a memoir documenting her draconian parenting style. Chua generated lots of publicity for her shock value anecdotes, like the time she threatened to burn all her daughter’s stuffed animals as consequence for playing poorly on the piano. Chua claims that her parenting techniques were not only typical of Chinese immigrants, but explained why Chinese Americans, on average, have educationally outperformed other ethnic groups.

Three years later, Chua collaborated with her husband and fellow Yale law professor, Jed Rubenfeld, to write a book that makes even bolder claims about how cultural differences explain group disparities in success. In The Triple Package: How Three Unlikely Traits Explain the Rise and Fall of Cultural Groups in America, Chua and Rubenfeld argue that a unique combination of three personality traits are the magic formula behind achievement. The three traits are: a belief in the superiority of one’s own group, a tendency towards feelings of insecurity, and the ability to control one’s impulses. According to the book, individuals who belong to cultures that emphasize these three traits tend to do better. As examples of their theory at work, Chua and Rubenfeld point out the greater success of Mormons, Nigerians, Persians, Cubans, Indians, East Asians, Lebanese, and Jews.

Chua and Rubenfeld’s book was met with harsh opposition, particularly from Asian Americans who objected to what they saw as the perpetuation of the “model minority” stereotype — the idea that Asian Americans tend to do well because of a cultural emphasis on work ethic, family values, and conformity. (Chua is Chinese.) Like all stereotypes, the model minority stereotype ignores the vast diversity within the Asian American population as well as the challenges faced by many people within that group.

The book also received praise from critics who lauded its frank discussion of an important question: why do some groups in America, on average, tend to do better than others? If one examines Chua and Rubenfeld’s theory closely, it becomes apparent that it is ultimately psychological rather than cultural: they propose that a specific combination of psychological traits can explain success, and they believe that people from certain groups are more likely to possess them. Joshua Hart and Christopher Chabris, both psychology professors at Union College, decided to empirically test the “triple package” hypothesis, using two studies with a combined online sample of over 1200 adults of various ethnic backgrounds.

The researchers deliberately chose to study a sample of representative Americans, rather than members of the successful groups mentioned by Chua and Rubenfeld, since this would offer a stronger test of the theory. If the presence of these three traits predict success, regardless of one’s ethnic or cultural group, then one might more confidently conclude that it is the combination of traits – rather than some other reason – that leads to greater success.

The triple package’s first trait, a belief in the superiority of one’s own group, was measured with a scale that asked respondents how much they agree with statements such as, “Most other cultures are backward compared to my culture.” Measuring insecurity, the second trait, proved a bit more complex because Chua and Rubenfeld argue in their book that insecurity can take many forms including low self-esteem, feelings of danger, or fear of losing what one already has. Therefore, the researchers measured insecurity using multiple scales. They combined their participants’ scores on these scales and identified the following three factors of insecurity: personal insecurity, contingent self-worth, and family insecurity. For “control,” the third trait, they used scales of impulsiveness, conscientiousness, and grit.

The researchers also measured their participants’ cognitive abilities through vocabulary and mathematical reasoning tests. Although Chua and Rubenfeld’s theory does not emphasize intelligence, past research has shown that general cognitive abilities are one of the strongest predictors of achievement and success. Finally, to measure life success, Hart and Chabris had their participants report on their annual income, level of education, and honors and awards they have received. All of these measures of success were combined to create a single, combined “success” variable.

The researchers used regression analysis to determine the strength of the relationship between the personality traits and self-reported success. The findings did not support Chua and Rubenfeld’s triple package theory of traits. The participants reporting the most success were not the ones who scored highly on all three traits. Instead, the biggest predictors of success were cognitive ability and parental education. Also, in direct contradiction to Chua and Rubenfeld’s theory, greater personal insecurity was related to less success in life.

There were, however, a couple of isolated findings that did support elements of the triple package hypothesis. Participants who scored higher on contingent self-worth reported greater success. People with high contingent self-worth tend to rely more on outer circumstances, such as the praise of other people, in order to feel good about themselves. It makes sense that people who have a high need for external approval would work harder to achieve outward success. In addition, there was a small but significant correlation between feelings of group superiority and attaining a higher income. In other words, the more hubris that participants expressed about their own ethnic group, the more money they reported making. Despite these individual findings in support of the theory, Hart and Chabris found no consistent evidence that it is the unique combination of the three traits – group superiority, personal insecurity, and impulse control – that leads to greater success.

If Chua and Rubenfeld’s theory can’t explain the success of certain groups, then what might? Hart and Chabris point out that, although it seems appealing to think that we can identify a group of learnable traits that determine success, there is scant evidence for such a formula. The idea of a “triple package” may seem compelling because it seems to fit with our own personal observations and common stereotypes about immigrants. In addition, the theory meshes well with the belief that success depends on one’s hard work and personal qualities, rather than one’s circumstances. But, as best we know, success is best explained by such unsurprising factors as being smart, being conscientious, and having the good fortune of growing up in a financially stable environment.