One of my favorite questions to ask people is “What do you want to be when you grow up?” The childhood question hits differently as an adult. It gets laughs, but it also implies you have some areas that are important to grow in. Luckily, human development is a studied topic.
Jean Piaget’s Theory of Cognitive Development
In 1919, Jean Piaget noticed "that children of different ages made different kinds of mistakes while solving problems". He postulated the theory of cognitive development where there were distinct stages of development usually associated with age ranges. There are four stages often with substages with the final one being reached around 14/15 years old.
To give an idea of this theory, in the pre-operational stage of development (2 -7 years old), children will be so egocentric they confuse their beliefs with those of other people. If they can see the card or love Pokemon, then you can see the card and love Pokemon. They also make the mistake of thinking pouring liquid into a taller pot means there’s more liquid or spreading the blocks farther apart means there are more blocks. Along with his theory, Piaget also developed some tests and important concepts that determine a kid’s stage placement.
Note that the idea of stages implies development isn’t just a linear accumulation of ideas, but more discontinuous jumps where children mature concurrently across multiple domains which changes the way they interact and understand the world. Other possible theories could be very domain-specific where there are specific stages for logic, science, egocentrism, language, etc. Or perhaps it could be understood more like linearly accumulating information like university coursework where there are specific courses you take to learn a specific thing. You can learn the history of the world in any order, but you must take Calc 1 before Calc 2. Or perhaps more emphasis could be placed on language, culture, and environment.
Jean Piaget’s study of children's development inspired the research on adult development looking for a similar concept of stages. But for that, we need another article
Maybe you should collect frameworks, like the designer of jetpack joyride talking about his game being bad because the intensity was boring because it was constant. The intensity was always high because you were always on your last life. By adding vechiles, you could take an extra hit and made the game more fun.
The whole concept of stages is very interesting. It reminds me of different startup stages/categories of preproduct, seed, Series A, etc. Where even having a stage or category for something implies there is something useful in the difference. There are stages of relationships, stages of a company, stages of grief, life stages. But what aren't there stages for and why? Anime fandom, nba games, jogging, pumpkins. Just the question, what are the stages of pumpkins is an interesting frame. It implies some important change across time that you can then categorize. Hmm.
It reminds me of Maslow's hierarchy. The concept of putting needs in a hierarchy implies you need one set of needs before achieving others. It implies prerequisites across domains instead of within a domain.