Defensive attitude. Sometimes the defensive attitude comes from a sense of lack of self worth, or feeling that the other person is not having enough compassion for the person we are. So we feel we have to bring up all the arguments to defend our ego. But it is more important to try to learn how to reflect on the eight worldly dhammas when we are not being blamed, so that we understand the importance of receiving constructive blame. Blame and praise in themselves are not the causes of happiness. Perhaps we had a good intention, but we lacked the wisdom that someone else has. Can we see this as a chance to learn how to do things more skillfully in the future. Then we can view criticism as an opportunity more meaning we have to protect our image so we think that the person will like us more.
It is seeking approval from others that brings up the defensive attitude, but if we have a more healthy sense of self worth, it is much easier to live with constructive criticism. A healthy sense of self worth is very important in order to be able to receive any criticism. Also reflecting on the benefits of having a guide is very helpful. As well, what you could try to do is use the Four Noble Truths more in your interactions. I know in the beginning when I was teaching, sometimes people would criticize me and if it was unjustified there would be some subtle reaction within me, although they may not have seen it. This happened for awhile until I realized, I have to use the Four Noble Truths more in my interactions here. I have to get below the personality level and learn how to see Dukkha. Do I have this Dukkha? Or is it their Dukkha? Depersonalizing the situation and just seeing Dukkha, the cause of it and asking myself what do I know about the ending of it.
If a person is trying to help you in some way and if they are pointing out a problem that you do have, then ok, this is your Dukkha. And if they are giving some methods on how to end it, then you can try to accept it, without taking it personally. If it is unjustified, then you try to see their Dukkha. That is seeing the hindrances externally. Learning how to see the suffering behind the hindrances and dropping down below the personality level to see the deeper truths in the situation. So using the Four Noble Truths in our interactions helps us to be less defensive and have more equanimity.