For children it is sometimes hard to see things from others perspective, in this case from the victims perspective. However these emotional skills can be trained. I have previously used second step program and often suggested it to kindergarten and elementary school teachers to use. (http://www.cfchildren.org/second-step). Also KIVA school program has extensive research background (http://www.kivaprogram.net/) and can be highly recommended.

Petteri Simola, 

Many thanks for your reply. Can you please clarify, this emotional state in 3-5 year olds? and if there is a clear plan for their emotional training? Should such children in the aggressor's group be isolated from that group or friendship circle? Would such strategies help? Is there any other strategy apart from time inside, time out or positive statements and rewards? If these strategies fail, then what is the best course of action for teachers as well as parents?

The concept of enjoying giving pain to others not because you are happy that others are in pain but just because you feel that it is a game...teasing others gives you natural pleasure...that teasing cane be in the form of bullying, torturing and so forth. What kind of public law can prevent children from bullying others?

There you get my point! Now the question is how can they be educated in the presence of such genetic tendencies? Is there any research evidence? Can they substitute one habit for another; for instance another positive way to get the peak of adrenaline which would be a replacement for the current bear-like behaviour? What is the role of teachers and parents? How can such children be prevented from engaging in teasing behaviours with their siblings? What kind of intervention would be useful during the occurrence of such behaviours other than punishment and time out?

Let's say sadism which occures in children is some form of indeed interpersonal interaction. And I agree with Petteri and Bernard: Children do not have the emotional controll (most) adults have nor have they internalized standards and regulations. In an environment in which one promotes some kind of "let it go" education (and sadly but true especially when it comes to children and violence adults tend to accept it as a game and not as bad as violence between adults; I hear that very often that parents say their violent breed is just a child and violence is like normal not comprehending that there is some border noone - not even children - should cross) there are no clear standards nor regulation which guide children. I think society has two problems: First we came to an understanding that children are not little adults giving them more room and time to learn. However especially when it comes to violence many people let it pass as long as a child did not reach a certain age (so we speaking here about age as a criteria and not what the child did). As Petteri said: Social training to raise awareness for empathy might be helpfull. But also direct intervention in form of inclussion and giving children a feeling of they belong to each other. While at the same time you might not forget they are children and they need fights and harsh interactions like every baby animal in order to develope skills. However this has to be agreeable with social standards. And it could be helpfull to teach children certain brief ideas about borders not to cross. Because what I think is: Aggression in itself is something one should not deny or completly get rid of like it is something really bad one come what may should deny.