I would think of it as harmless, depending on the child, for example if the child is lonely a robot could serve the purpose of being a friend to the child.  on the other hand you don't want the child to be so engrossed with it that he or she has no human friends.  So what i think i'm trying to say is that they can be either harmless or harmful, all depending on the child.

"Life is not measured by the breaths we take, but by the moments that take our breath away."

As a parent of 3 teens, my kids have "outgrown" toys. Unlike their dad, who may be getting older, but who refuses to get more mature.

My children have had electronic and motor driven toys of various types over the years. They included simple toys like Alphie, which used cards, buttons, and lights to play matching games. There were also more complex toys like Lego MindStorm programmable controllers. 

My advice to parents is to pay attention to the suggested age ranges and gauge them against your specific child's abilities and interests. A robot that's immediately useable out of the box might be a better match for a child who doesn't like to follow instructions to assemble or program things.

Depending upon the robot it may be susceptible to damage if the joints are either held in place when they are trying to move, or forced beyond their normal range of motion. 

From the other side of the damage spectrum, it's also possible for little fingers to get caught in crevices and pinched when joints move. 

Either event is sure to bring on tears for the young at heart.

A robot can be an entertaining diversion. The very young will enjoy how the robot can sense and react to what's around them. It's seemingly unpredictable, and that can either delight or frighten a child, depending on how comfortable the child is with moving toys. 

For the older children who want to teach their robot new tricks, there are different levels of interaction available. Some robots can be taught by moving the joints by hand. The robot remembers how the movements were made, and can recreate them. A child of almost any age can teach a robot using that technique.

A more sophisticated teaching technique might involve use of a remote control to string together a group of commands stored in the robot. 

For those technical minded robot owners, there are robots that can be programmed using a personal computer. Special software is used to write complex behaviors that can be transferred to the robot.

ScottE -- Member (always) & Moderator (when needed)