“But my kid is too young to know they’re transgender! This is such a big life decision and I don’t think they’re old enough to make it.”
This is scientifically incorrect! Studies show that gender identity develops around the age of 3-5 years old [11, 13]. While this doesn’t mean that every kid realizes that they are transgender as a toddler - social and parental pressures as well as general societal stereotypes of gender can cause many transgender individuals to remain presenting as the gender they were assigned at birth for many years - it means they absolutely CAN. The argument that kids are “too young” to be able to know who they are is scientifically and psychologically incorrect. Kids absolutely are capable of knowing their gender identity.
"But their brains haven't even matured yet! They can't make decisions like this!"
Gender identity is not a decision. Being transgender is NOT a decision. It is part of who we are.
When people present argument about executive function, they fail to understand that they are conflating two different cognitive areas.
Let’s get into the neuroscience–
The prefrontal cortex (PFC) is the center of executive function. Executive functioning does not mature until mid to early adulthood  and is often referred to as cognitive or self-control. This skill set includes the following three skills: cognitive flexibility, working memory, and inhibitory control . Inhibitory control includes the ability to hone attention and focus, ignore distractions, and inhibit or regulate base emotions and impulses. Inhibition is often very useful and allows us to adhere to social rules and function in society appropriately, but it also allows us to inhibit our very identities. If you’re an adult, you’ve likely experienced this. Everyone inhibits (or hides, avoids, doesn’t show) pieces of themselves for various reasons when they interact with others.
But kids do not have this inhibitory control — they do not have the mature neurological pathways yet to enact it. As a result, kids have a unique ability to express themselves exactly as they are, because that is all they have. They have not grown up to learn who they are supposed to be, so they are just who they are.
That is, mature executive function could actually reduce the ability for a person to be able to openly speak their mind and express their authenticity because mature executive function allows for a heightened ability to inhibit oneself — and potentially could allow a trans person to inhibit their expression of self due to fear or some other hesitation.
“But some people do regret their transition!”
Yes, they do! No one is declaring that no one ever regrets transition. The research shows that almost no one does . This is statistically true. A handful of folks do de-transition and realize that they are actually their assigned gender. This handful out of the literaly millions of transgender people in the world is statistically insignificant. Additionally, I have read zero accounts/case studies of folks who regretted transitioning or who de-transitioned who thereafter experienced significant psychological harm or distress. They usually express that the experience wasn’t for them, and they actually would rather live in the gender they were assigned at birth. Compare this with increasing suicide attempts by 3.5x due to rejection of identity . It is always better to affirm, even if it means that (less than) 1% of the time, the person might not be transgender in the end. They are more likely to be alive if you affirm them. They might not be if you reject them.
Check out this video for a summary of why kids are NOT too young to know they are transgender: