IQ has been the subject of hundreds, if not thousands of research studies. Scholars have studied the link between IQ and race, gender, socioeconomic status, even music. Discussions about the relationship between IQ and race and the heritability of IQ (perhaps most notably Steven Jay Gould's Mismeasure of Man) often rise to a fever pitch. Yet for all the interest in the study of IQ, there has been comparatively little research on other influences on performance in school.

Angela Duckworth and Martin Seligman estimate that for every ten articles on intelligence and academic achievement, there has been fewer than one about self-discipline. Even so, the small body of research on self-discipline suggests that it has a significant impact on achievement. Walter Mischel and colleagues found in the 1980s that 4-year-olds' ability to delay gratification (for example, to wait a few minutes for two cookies instead of taking one cookie right away) was predictive of academic achievement a decade later. Others have found links between personality and college grades, and self-discipline and Phi Beta Kappa awards. Still, most research on self-discipline has achieved inconsistent results, possibly due to the difficulty of measuring self-discipline. Could a more robust measure of self-discipline demonstrate that it's more relevant to academic performance than IQ?

To address this question, Duckworth and Seligman conducted a two-year study of eighth graders, combining several measures of self-discipline for a more reliable measure, and also assessing IQ, achievement test scores, grades, and several other measures of academic performance. Using this better measure of self-discipline, they found that self-discipline was a significantly better predictor of academic performance 7 months later than IQ.

How did they arrive at this result? They studied a group of 8th-graders at the beginning of the school year. They used five different measures of self-discipline: the Eysenck Junior Impulsiveness scale (a 23-question survey about impulsive behavior), the Brief Self-Control Scale (13 questions measuring thoughts, emotions, impulses, and performance), two questionnaires in which parents and teachers rated the student's self-discipline, and a version of Mischel's delay of gratification task. Students were given an envelope containing $1, and were told they could spend it immediately or bring it back in a week for a $2 reward. The students were also given an IQ test (OLSAT7, level G).

At the end of the school year, students were surveyed again and several measures of academic performance were taken. The data included final GPA (grade point average), a spring achievement test, whether they had been admitted to the high school of their choice, and number of hours they spent on homework. All except two measures correlated more strongly to self-discipline than to IQ. Scores on spring achievement tests were correlated both to self-discipline and IQ, but there wasn't a significant difference. Duckworth and Seligman suggest that this could be partially due to the fact that achievement tests are similar in format to IQ tests. The other area where there was no significant difference was in school absenses.

Most impressive was the whopping .67 correlation between self-discipline and final GPA, compared to a .32 correlation for IQ. This graph dramatically shows the difference between the two measures:

Both IQ and self-discipline are correlated with GPA, but self-discipline is a much more important contributor: those with low self-discipline have substantially lower grades than those with low IQs, and high-discipline students have much better grades than high-IQ students. Even after adjusting for the student's grades during the first marking period of the year, students with higher self-discipline still had higher grades at the end of the year. The same could not be said for IQ. Further, the study found no correlation between IQ and self-discipline—these two traits varied independently.

This is not to say this study will end the debate on IQ and heredity. The study says nothing about whether self-discipline is heritable. Further, the self-discipline might be correlated differently with achievement for different populations; this study covered only eighth graders in a relatively privileged school. Perhaps self-discipline has a different role at other ages, or in more diverse populations (though the study group was quite ethnically diverse—52% White, 31% Black, 12% Asian, and 4% Latino). Perhaps the most important question which remains is how best to teach children self-discipline—or whether it can be taught at all.

智商曾经是成百上千的研究者的主题,学者们曾经致力于研究智商和种族,性别,社会经济状况,甚至音乐等之间的关系.有关智商和种族关系以及智商遗传性的讨论也非常热(可能最有名的是 Steven Jay Gould 的<关于人类的误区>).然而,所有对智商感兴趣的研究中,有关智商在学校表现影响方面课题则较少.

Angela Duckworth 和 Martin Seligman估计,有关智商和学业成就关系之间的论文中,只有不到十分之一的文章提到了自身努力.即便如此,这些小比例关于自身努力的研究也只是认为"它对成功有重要影响 ".Walter Mischel 和 colleagues 发现二十世纪八十年代,四岁的孩子延长快乐的能力(比如手上有两块饼干会等一会再吃掉他们,而不是先吃掉一块再说)成为了年后学术研究的对象.而另外一些人则发现了个性和学业成绩之间,以及自身努力和大学优秀生之间的关系.很多关于自身努力的研究出现了相互矛盾的结果,或者这要归罪于自身努力的难以量化. 是否能出现一个更有说服力的证据:自身努力对学校成绩的影响大于智商?

为了落实这个一问题, Duckworth 和Seligman对八年级生进行了一项为期两年的调查,为了更可信,采用了很多自身努力的量化参数,也测试了智商.学业成绩,年级以及很多其他在校表现.籍此,他们发现,自身努力比智商更明显的预言了学生七个月后的表现.

如何得到这个结果的?他们从学年开始就对八年级学生进行调查,使用了五项不同的自身努力量化参数:Eysenck初级冲动数(有关冲动行为的23个问题), 自我控制系数(关于思考,情绪,冲动和表现的十三个问题),两个问卷由老师和家长评定该孩子的自我修养,还有一个Mischel的自我满足测试任务.(给孩子们一个装了1美元的信封,告诉他们可以马上花掉它或者一个星后用它换2美元).同时也给他们做了智商测定.

学年结束后,孩子们又接受了调查,还拿到了他们的成绩单.最后的数据包括各科平均成绩,成绩弹性度，他们是否通过了己理想高中的录取,每天花在家庭功课上的时间等等.所有这些除两个以外都和自身努力有莫大关系,与智商之间的关系却很少, 成绩弹性度与智商及自身努力都有关系,但是并不是根本性的不同,Duckworth 和 Seligman认为,这或许要归咎于成绩测试智商测试很相似.另一个对二者而言没有什么不同的因素是学校的出勤率.

最后,自身努力和最终平均成绩之间67%的吻合度给人留下深刻印象,而与此对应的是,智商仅仅与其有32%的吻合度.从下面的可以明显看出来.

智商和自身努力都和平均成绩有关,但是自身努力是一个相对更加重要的因素,那些自身努力不够的人比智商略逊的人成绩差,当努力的学生取得的成绩要高于高智商的学生.就算在一个学年标志性结束后调校了学生等级,很努力的学生也在年终取得了好成绩.但是高智商的学生却表现平平.而且,研究表明智商和努力之间没有任何直接关系--它们各自独立.

并不是说这个研究会终结关于智商和遗传的争论,这个研究根本没有涉及自身努力是否可遗传.相反,自身努力对不同的人来说,能对成功会起到不同的作用.这个研究也只是在一个学校的八年级取得结论而已.或许自身努力在其他的年龄段它会扮演不同的角色,或许对不同的人种也有不同的效果(研究包含了52%的白人,31%黑人,12%亚裔,4%拉丁裔).

或许,剩下最重要的事情是如何教育孩子奋发努力(如果能教育的话).