Not really negatively manipulative IMO, I've worked with many people who don't really understand taxes and they think that a refund is some kind of free money "bonus" and often use it to make frivolous purchases and blow the whole refund at once. Most of these people don't really plan or budget on how to use their refund because they have no idea how much it's going to be, it's just treated as kind of a random winfall.

Doling that out in smaller increments and making the purpose specific (child credit, instead of tax refund) seems like a good nudge into better spending habits... especially when the amount is known ahead of time.