Before the age of 3, a child who does not play with their father may develop a personality trait that will follow them throughout their life. It is often assumed that adults who remain calm have naturally composed personalities. However, behind this self-control often lies a specific story: that of a parent, often the father, who has engaged in playful, physical interactions—roughhousing, carrying, tickling—all within a structured framework. These seemingly simple moments can leave a lasting imprint on a child's ability to control impulses. For nearly four decades, researchers have studied dozens of studies on father-child play and its effects on self-control. Their findings consistently show that children whose fathers often play with them, especially before the age of 3, tend to develop better emotional and behavioral self-regulation, fewer behavioral problems, and less hyperactivity later in life. The ability to control anger, delay gratification, and tolerate frustration can change the course of a life. However, part of this ability is shaped in early childhood through specific, concrete interactions, long before school or lessons on "calm down." An analysis of 78 studies conducted over approximately four decades, published in Developmental Review, shows that most fathers play daily with their children, but with a particular style: carrying them on the back, tickling, chasing, or playing "pillow fights." This physical father-child play, more common among men than women, is especially linked to better self-regulation when the child is under 3 years old. Children who benefit more from this type of play later show fewer emotional difficulties, fewer behavioral problems, and a reduced risk of hyperactivity. However, researchers from Cambridge remain cautious. "It is important not to exaggerate the impact of father-child play because what the research can tell us has its limits," explains Professor Paul Ramchandani, as quoted by Psyblog. "But it seems that children who have a reasonable amount of play time with their father benefit as a group." In other words, play does not do everything, but it constitutes a privileged training ground for developing self-regulation skills. Professor Ramchandani explains what is at stake in these moments of controlled roughhousing. "Physical play creates fun and exciting situations in which children must apply self-regulation. They may have to control their strength, learn when things have gone too far, or perhaps their father accidentally steps on their toe and they feel upset." In this safe environment, children can practice responding appropriately. If they react in the wrong way, they may be scolded, but it is not the end of the world, and the next time they may remember to behave differently. Each game allows the child to learn how to modulate their energy, hear a "stop," and return to calm after an excitement spike. These micro-skills will later support an adult's ability to hold back hurtful words or resist impulsive buying.