According to research published in the journal Cognitive Science, toddlers can figure out when their parents are joking, with the help of clear social cues. For example, if a parent holds up a cup of water to their elbow (as though they’re offering their joint a drink), exclaiming “That’s not how you drink!” helps their child understand that they’re joking. (Without that hint, kids might be left wondering if their elbows are, in fact, thirsty.) The study also found that kids can differentiate between joking and pretending—two activities that, though similar, may contribute to a child’s development in somewhat different ways. Elena Hoicka, a developmental psychologist and one of the paper’s authors, describes the potential benefits that sharing a beverage with your elbow, throwing a rubber chicken on your head, and galloping a block as if it's horse can have for kids.