Possible but I don´t think so.. A boxing glove obviously protects the hand more but it its still easy to hurt your hands. A lot of boxers frequently fracture their hands during fights, Mayweather J and Arturo Gatti come to mind. If I remember correctly the only knockdown of Mayweather Jr:s career was due to him breaking his hand on someones head. So I don´t think that boxers as opposed to MMA-fighters "feel safe" and throw punches with wild abandon. Also you could argue that maybe boxers fear hurting their hands more than MMA-fighters and therefore hold back; being unable to punch is obviously a bigger problem in boxing than in MMA.