It would enable it to default to certain IQ based skills.
That's the reason IQ is fairly nice. Tons of skills are IQ based.
In this game, you succeed on a task by rolling dice and getting a result lower than your IQ and skill Mod.
If, for example, you have Computer Hacking at IQ-2 [2] and 12 IQ, then you would have to roll below a 10 to succeed in hacking something. If you had IQ 14, then you'd have to get below a 12.
You raise stats if you want to use a bunch of skills relating to that stat, or if you want something from that stat.
“She'd become a governess. It was one of the few jobs a known lady could do. And she'd taken to it well. She'd sworn that if she did indeed ever find herself dancing on rooftops with chimney sweeps she'd beat herself to death with her own umbrella.”
― Hogfather