The role of dopamine and serotonin in, respectively, creative and analytical thought processes is well established. So, the title of the study can probably be changed to "Dopaminergic dominance yields more correct solutions compared to serotonin dominance". While too much analysis is definitely a sign of suboptimal metabolism (and often of mood disorders like depression) the performance of the analytical thought was not that far behind than the insightful one. I think analytical thought is simply what remains when metabolism is not sufficient to support creative, inductive thinking - i.e. the analytical thinking is possibly a baseline / survival mode of thought in suboptimal environmental conditions.
http://www.tandfonline.com/doi/abs/10.1080/13546783.2016.1141798?journalCode=ptar20
"...Of all responses labelled as insight, an average of 97.6% were correct (mean N of responses, M = 72.4; SD = 30.2); of all responses labelled as analytic, an average of 91.9% were correct (mean N of responses, M - 51.9; SD = 30.1). Significantly more insight responses were correct compared to analytic responses (t(50) = 2.78; d = 1.50; 95% CI [.01; .09]; p< .01); significantly more errors of commission were labelled as analytic than insight (t(50) = -2.79; d = .60; 95% CI [-.1; -.06]; p < .01)."
http://www.tandfonline.com/doi/abs/10.1080/13546783.2016.1141798?journalCode=ptar20
"...Of all responses labelled as insight, an average of 97.6% were correct (mean N of responses, M = 72.4; SD = 30.2); of all responses labelled as analytic, an average of 91.9% were correct (mean N of responses, M - 51.9; SD = 30.1). Significantly more insight responses were correct compared to analytic responses (t(50) = 2.78; d = 1.50; 95% CI [.01; .09]; p< .01); significantly more errors of commission were labelled as analytic than insight (t(50) = -2.79; d = .60; 95% CI [-.1; -.06]; p < .01)."