Is there any harm in forcing/re-educating a left-handed child to use their right hand?

Question

Backstory:

Many of my relatives were subjected by their parents to a "training process" to "prevent" left-hand-dominance. This method started at a very young age and basically consisted of politely instructing the child to switch hands whenever they reached for an object with the left hand. Now, as adults, everyone that went through this process—most of whom admit that they are genetically left-handed—uses their right hand for almost all tasks. Some have even developed ambidextrousness, which I guess is an added benefit.

Now, as my young daughter is reaching the age where this "process" should start, I wonder if I should resist my family members' suggestions to do the same for her.

Skepticism:

All of the parenting advice I've found on the Internet (e.g., pages like this) claim that forcing genetically left-handed children to use their right hand is bad. Most of their arguments, however, take the form of, "It isn't so bad to be left-handed, so why resist?" Or pseudo-medical claims that forcing right-handedness will conflict with the child's left-vs.-right brain dominance.

Question:

Is there medical/psychological/scientific evidence on whether forcing or re-teaching handedness is harmful vs. beneficial to a child's development?

_{I am not looking for opinions on whether it is a good idea to do this to one's child; that's why I'm asking this here as opposed to Parenting.SE.}

Answer 1

Reasons for switching?

Generally today, in the western world, left-handed people are equally accepted as right-handed people and should not experience any major drawbacks. Today, a child can easily work with the left hand. Thanks to some tools such as scissors, writing pads and pens for left-handed no problems are expected. If a child does have bad deal, because it has, for example, an unfavorable position when writing, there are recognized and specially-trained occupational therapists who can help.

What does switching accomplish?

So like you can read in the article "Can Left-Handedness be Switched? Insights from an Early Switch of Handwriting" from The Journal of Neuroscience, 18 July 2007:

These results suggest two distinct neuronal correlates of handedness in human sensorimotor cortex. Although those in executive sensorimotor cortex (i.e., SM1 and adjacent PMd) depend on the hand used throughout life, those in higher-order sensorimotor areas (i.e., inferior parietal cortex and rostrolateral PMd) are invariant and thus cannot be switched to the nondominant hemisphere by educational training.

Which says that the areas that are directly involved in movement control will move increasingly to the left in the brain, which is the dominant half in right-handers. But the larger regions that participate in the planning and control of movement remain all life in the same place.

Paradoxly those planning and control areas were even more stressed in retrained persons than in normal left-handers.

Problems of switching?

Even as early as 1918 [1] observations were made, were

[retraining]... may result in speech-hesitation. [...] Taking it all in all, this investigation seems proof conclusive that left-handed children should not be forced to use the right hand.

And a lot more studies from that time period (1930s) were linking stuttering to forced left-hand retrainment.

But since then no more professional studies have been made to investigate eventual problems with retrainment[2]. One of the reason for that is that left-handedness was long seen as a deviation from the norm and medical treatment or research was conducted purely from this perspective. Also many studies provide statements that refer to very different groups of people: generally assessed left-handed people, learned left handed and the subgroup of trauma-induced left-handed were all mixed together and no reasonable conclusions can be made.

Summary

So while it is not proven at this point that retraining is leading to serious problems (apart from the increased brain load) there are is also no point in doing it. All studies and logical reasoning hint for an exclusion of such practices.