In ABA blocks, reinforcement is obvious (edibles, tokens, praise). In PBB, therapists often forget to provide explicit reinforcement, assuming the play itself is reinforcing. But for target behaviors, you must still deliver social praise or small tangible rewards.
Reduplication (repeating syllables) is one of the most common features of catchy slogans and viral sounds. It creates a rhythm that is easy to replicate. "Aba aba" flows effortlessly off the tongue. The "pbb" ending provides a percussive release of air.
Think of other viral sounds that have dominated the internet: "Skibidi," "Dop Dop Yes Yes," "Bling Bling." They all rely on simple, rhythmic, open vowel sounds. Our brains love patterns, and "aba aba pbb" is a micro-pattern. It is an earworm that conveys no meaning but delivers maximum rhythmic impact
Researchers are also piloting virtual reality (VR) PBB environments where children practice social skills in simulated playgrounds after completing two ABA blocks in a clinic. Early results show higher engagement and faster mastery.
Put them together—"Aba aba pbb"—and you have the auditory equivalent of a toddler drooling, blowing a raspberry, and perhaps falling over. It is pure, distilled idiocy. And that is precisely the point.