Pronoun

Help me, please!

What does the underlined "they" indicate in the passage below? 'Nonsense and silliness'? or 'kids'? or 'adults'?

By any chance, if "they" means "adults", does the sentence seem right to you, English native speakers, in terms of context?

Probably the biggest roadblock to play for adults is the worry

that they will look silly, improper, or dumb if they allow themselves

to truly play. Or they think that it is irresponsible, immature, and

childish to give themselves regularly over to play. Nonsense and

silliness come naturally to kids, but they get pounded out by norms

that look down on “frivolity.”