how to characterize it;

把这一标准形象的描述出来
this is what research does,

这就是研究的目的所在
but there's a gut feeling

但是直觉告诉我们
that there are some people who are smart

有些人聪明
and other people who are very smart

有些人更聪明
and some people who are dumb and others who are very dumb.

而有些人愚蠢甚至有人愚蠢至极
What you want to do, from a scientific standpoint,

从科学的角度来说你需要做的
is characterize this in a more robust and interesting fashion.

使用一种更有力更形象的方式来描述智力
And the textbook has a nice review

课本上有一段精彩的综述
of the history of attempts to define and measure intelligence,

讲述了定义和评价智力的种种尝试
but there is a couple of ideas I want to focus on.

但是有几点我们需要重点关注
One is an idea developed by Spearman,

一个是由斯皮尔曼提出的观点