In general terms, there are four types of complaints – productive, venting, chronic, and malicious – and four varieties of complainers – aggressive, expressive, passive, and constructive.

In customer service psychology, complaints are generally categorized into four personality-driven types: The Passive, The Aggressive, The Constructive, and The Expressive. Passive complainers are the most dangerous to a brand; they rarely complain to the company directly but will tell friends and family about their bad experience, quietly taking their business elsewhere. Aggressive complainers are vocal and demanding; they want immediate results and often display high emotion, requiring a calm, firm, and solution-oriented response. Constructive complainers are the most valuable; they provide detailed, logical feedback with the goal of helping the company improve, often expecting a fair "fix" in return. Finally, Expressive complainers seek validation and social proof; they are the most likely to post their grievances on social media or review sites. Understanding these types helps businesses tailor their recovery strategies—ranging from deep technical fixes for the constructive type to public empathy for the expressive one.