Did the serum work too well on mango or was he so dangerous that he needed to be baby sized?

isadoraarkham:

The serum, as Porkrind said was something they had been lucky with…they are still fiddling with the dosages and with different types of characters it reacts either too strongly…or not strongly enough….Mangos due to his chaotic nature and lack of any real body seemed to work too well. I certainly feel that Mangosteen actually never spoke using words….and now as a baby ball…he speaks in little chirrups and whistles and seems much much happier.