Want your kid to stop whatever dangerous/annoying/forbidden behavior he’s doing right now? Spanking will probably work — for now.But be prepared for that same child to be more aggressive toward you and his siblings, his friends and his eventual spouse. Oh, and get ready for some other antisocial behaviors too.A new analysis of two decades of research on the long-term effects of physical punishment in children concludes that spanking doesn’t work and can actually wreak havoc on kids’ long-term development, according to an article published Monday in the Canadian Medical Association Journal.