Complex sentence: Critics such as Keith Stanovich do not dispute the reliability of IQ test scores or their capacity to predict some kinds of achievement, but argue that basing a concept of intelligence on IQ test scores alone neglects other important aspects of mental ability.
Split into simpler sentences: Critics such as Keith Stanovich do not dispute the reliability of IQ test scores or their capacity to predict some kinds of achievement. But they argue that basing a concept of intelligence on IQ test scores alone neglects other important aspects of mental ability.