Doubt on the trope "power trio": what are their psychological basis?

Question

I will gather some non-standard characters in this question. Suppose then the Powerpuff Girls, Team Sonic, Totally Spies, Kanker Sisters (Ed, Edd n Eddy), and so on.[1]

Every time we can identify some external characteristics: The "gothic" personality, the "barbie" personality, and the "neutral/leader" personality. This is, of course, is a quite rough, imprecise analysis. But still, this trope forms a dynamic relationship quite interesting (which seems to work pretty well).

For instance, in the Powerpuff Girls, we have Buttercup and Bubbles; one is quite the opposite of the other: Buttercup has a destructive and impulsive personality, instead Bubbles is the most sensitive of the three, a bare wire of emotion. Then we have Blossom, some sort of a mediating factor between the two other girls.

It seems that these power trios are created when we "break the uno-persona." In other words, it seems that these three personalities can fit into a single character. But these characters (in power trios) seems to have just one single personality.

I would like to know: what are the psychological fundamentals of a power trio trope?

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[1] https://www.gameskinny.com/bm24v/girl-power-5-female-driven-trios-that-deserve-their-own-video-games

Answer 1

Power trios are often "Freudian trios."

One of the best arguments I've seen about the psychology of power trios is that each trio has a character that loosely represents Freud's psychoanalytic theory of mind. That is, there is one character each for the id, superego and ego, where

• the id character is impulsive, emotional, and/or primarily driven by social needs. They are often the troublemaker, loudmouth, promiscuous flirt, or extrovert of the group. They are also often not very intelligent and can be the "dummy" of the group, but they have "street smarts."
• the superego character is logical, deductive, morally upright, and rigid. They are often inflexible and stick firmly to their beliefs. They are also often religious or have a strong moral code. They are also usually the "nerd" or "brain" of the group and are typically of higher intelligence.
• the ego character is the leader of the group and mediates the competing desires of the superego and id to make decisions on behalf of the group, which creates the interesting power dynamic and character interactions for the trio. They typically have some superego and some id characteristics, making for a more balanced and neutral character than the others.

Famous examples

As an example, a very famous power trio is that of Captain Kirk, Spock and Bones in Star Trek: The Original Series. One of the show's writers compared them to the id, ego and superego, with Bones representing the impulsive and emotional id, Spock representing the logical, perfectionistic and deductive superego, and Captain Kirk representing the middle, leadership role of the ego whose job it was to negotiate the competing demands of the superego and the id - that is, the competing demands of Spock and Bones, who in each episode would clash over their different approaches to problems.

Another example is in The Big Bang Theory, with Sheldon being the inflexible and rigid superego, Penny being the promiscuous and impulsive id, and Leonard being the mediating ego who is smarter than Penny but has better social skills than Sheldon.

See the TV trope "The Freudian Trio" for many more examples.