Computational thinking is an important skill in computer science since the 1960s, and it is closely related to problem solving. Almost all research related to computational thinking mentions problem solving. Although some research has been conducted on computational thinking, few studies examined the impact of personal traits on students' computation thinking skills and problem solving. This study modeled cooperative attitudes of programming, learning style, self-regulation, and enjoyment as its key elements, investigated personal traits as predictors of problem-solving skills, and examined the correlation between variables and computational thinking. The 252 research participants were all sixth-grade students in an elementary school in Taipei, Taiwan. After a 10-week experimental curriculum, a posttest was conducted, and a total of 244 observations were collected. Correlation and regression analyses show that computational thinking is positively correlated with problem-solving skills, and learning style has the predictive ability for computational thinking. Furthermore, cooperative attitude and self-regulation of programming are important variables for predicting problem-solving skills; the degree of students' enjoyment in the curriculum will affect the cooperative attitude and self-regulation of their programming. In summary, the personal traits above could improve the participants' problem-solving skills hierarchically and help them achieve better computational thinking.