Hey,
I would very kindly like to ask for suggestions in regarding self-help/ psychology books on the topic of self-esteem and self-assessment.
I have a close friend (a man in his mid-twenties) I would like to find a book for. On the surface he is very amicable but struggles with underlying passive aggressive behavior triggered by what seem like deeply hidden insecurities, resulting in his struggle to empathise and communicate with the people closest to him. I have looked around but as there are many professionals here, maybe you could recommend something specific? He is an avid reader of factual literature and I am sure he would welcome a deeper focus on a scientific point of view that is at the same time suitable and engaging for an amateur reader.

Thank you very-very much!