Development of Strategic Thinking Driven by Sexual Maturation?

Tonight I met Rob Maher - an inspiring and dear friend of mine. We discussed the art of designing a teaching environment where we can ignite the curiosity of kids and leave them in the state of flow. The art of embedding tools allowing kids to discover for themselves while maintaining structure of the acquired knowledge and skills.
While discussing we came into the issue of delayed and instant gratification. We found out that it is related somehow to curiosity. We observe kids staying in flow for 35 - 40 minutes once ignited. Same kids, who are procrastinating and not focusing when faced with solving math problems.
Pre-adolescent kids who have been told about the importance of making decisions to prioritize on their long term goals state their conscious motivation but still do not cope well despite their understanding of the future benefits.
We theorized that delayed gratification is developed as a functional capability later in kids' life. As babies and toddlers socialize actively it seems socialization itself is not dominant factor igniting such functional development. Looking briefly at the literature, I was surprised to find out evolutionary theorists spent time arguing the opportunity cost of delayed gratification in food selection. No one seemed to have looked at another reason - mate choice.
It is in puberty when the pre-frontal cortex undergoes its most significant development. We know delayed gratification develops at that age. Sex drive and priming requires capacity to plan and wait. To delay gratification. Does selection would prefer individuals having better abilities in delaying gratification? In a species where sex is a tool for social interaction and evolution, mate selection could play a role in the evolution of the complex strategic thinking.
The capacity to delay gratification is developed in puberty as part of the strategic (long term) thinking ability connected with the need to reproduce.
One way to test the hypothesis is to look for effects of age in decreasing the symptoms of ADHD. ADHD should decrease mostly among children aged 12-18. Indeed literature supports this fact.
It is up to the professional scientists now to develop experiments to test this.