Hi Robert—Thanks for your comment! You are absolutely right…many of the tools and techniques we use when designing for kids can apply to adult audiences, too. The examples in this chapter around help and feedback and challenge are especially relevant.
What you’ll want to do before using these techniques is to (1) make sure that whatever you’re designing for an adult audience lends itself to these approaches; and (2) make sure the interactions are subtle enough to appeal to adults without getting in their way. For example, if a customer is checking their retirement-fund balance, they’re not going to want it to feel social. And, while kids love in-your-face feedback, too much/too intense/too persistent feedback is annoying for adults.