The author claims that we learn more when we speak with people who share our views than with people who contradict them. This is because disagreement cause stress and therefore inhibits learning. I generally do not agree with this statement for the following reasons.
First, through discussion with somebody who does not share one’s point of view, we extend our knowledge and learn more. If we only discuss with people, who share the same ideas as we do, we will not learn something new; we only strengthen our bubble effect. The bubble effect describes how we often share a similar mindset with people that surround us, like our family and friends. Therefore, discussion with people from another region, education, or another age might open us a different perspective.
Further, when we only discuss with people who share our views, we often are tempted to ignore the problematic aspects of a subject. For example, suppose you watch a debate about a new law that might get implemented. In that case, you will not learn much from this discussion if the speakers are members of the same party. They only raise the positive aspects, what this new law could bring up. But, if you watch a discussion from people with different opinions, the debate gets much more enjoyable. You will hear about the challenges of a potential implementation of the law and therefore have a broader perspective about the topic.
There are situations where I agree with the author's claim that disagreement can cause stress and inhibit learning. Disagreement is often linked to stress and anger, especially if the two parties are very convinced of their ideas. This you might be seen in political debates as well. Those discussions often get very emotional, and nobody is ready to see the other’s perspective. Further, it is essential to communicate gently. Suppose you want to convince somebody of an idea. In that case, it is not effective to show them how stupid their idea is, but, if you show them the possible advantages, that might effect them, you might change his/her mind much easier.
In essence, I think one might learn more from disagreement because it shows you another perspective that you maybe did not realize. Further, discussion with people who only share our views will strengthen your bubble-thinking, which closes the open-mindedness to other opinions. It is crucial how we communicate with other people. While criticism will not help convince somebody of our opinion, rather than getting the other person in a defensive position, a calm and empathic argumentation might work much better.