Issue 1: we can usually learn much from people whose view we share than from people whose views contradict our own; disagreement can cause stress and inhibit learning.
We usually get knowledge from people who agree or disagree with us. But whether there are evidences to illustrate that we learn more from the former than from the latter just as the speaker claims? I have a different view.
I admit the fact under some conditions people harvested nothing from an argument or a controversy except for a heap of contumelious words and meaningless complaints. On some debates today, the combatants put all irons in the fire to manifest their own view of point; furthermore, they neglect their opponents’ standpoint. The spectators pay no attention to what players have said but are mostly allured by meaningless rhetorical skills and shouting bouts.
And sometimes people who express dissent due to their different subject or knowledge background. A vegetarian rejects eating meat while a flesh-eater does contrarily even they both have the same goal, to be healthier. Under the control of the prejudice, they cannot persuade each other let alone learn from each other.
In terms of what I have mentioned above it seems that disagreement may inhibit learning. However, I disagree with the speaker’s claims. I attribute this headspring of the chaos which I mentioned above to the misunderstanding of the essential meaning of the argument and debate. For supporting examples we need to talk about Aristotle who is famous for his declamations. At that time, the era of Ancient Greece, famous speakers like Aristotle, Plato, and Socrates argued in debate not for victory but for pursuit of verities. Nowadays people throw away the true value of debate and turn to pursue a win against their opponents. It is wrong and results in the barrier of learning from others who disagree with them.
Actually learning from others whose view contradicts our own promotes the development of our science. Assuming people who disagree with our view come to an agreement with us on fundamental assumption, the argument may exist on the logic or the discursion. We can learn by understanding other’s view to perfect our own. The other circumstances are that people disagree with our fundamental assumption. It may be caused by different subject backgrounds or different views of point. We also can learn different subject knowledge from others. In fact, mostly the bifurcation will not be eliminated but at least it offers a new view of point from which we discuss the issue.
As a conclusion, I concede disagreement can inhibit learning when people all willing to win the debate or the argument. Aside from this instance, rational argument and debate can benefit our knowledge advances.