The wireless microphone fed into a recorder that ran for several hours. If the toddler had a meltdown during that period, the researchers obtained a high-quality audio recording. Over time, Green and Potegal said they collected more than a hundred tantrums in high-fidelity audio.

The scientists then analyzed the audio. They found that different tantrum sounds had very distinct audio signatures. When the sounds were laid down on a graph, the researchers found that different sounds emerged and faded in a definite pattern. Unsurprisingly, sounds like yelling and screaming usually came together.

“Screaming and yelling and kicking often go together,” Potegal said. “Throwing things and pulling and pushing things tend to go together. Combinations of crying, whining, falling to the floor and seeking comfort — and these also hang together.”

But where one age-old theory of tantrums might suggest that meltdowns begin in anger (yells and screams) and end in sadness (cries and whimpers), Potegal found that the two emotions were more deeply intertwined.