Is there experimental evidence for the effectiveness of disciplinary spanking? A review and Meta-analysis of four controlled trials

We found that the trials lack internal and external validity. The meta-analyses that incorporate these trials usually do not assess spanking against other cooperation-eliciting strategies, are sometimes flawed, and reach inconsistent conclusions. The current analyses showed no significant difference between spanking and other cooperation-eliciting strategies combined; g = 0.24, standard error = 0.26, t(27) = 0.91, p = .37).