Research by Robert Vallorand distinguishes between two types of passion: obsessive and harmonious. Obsessive passion is characterized by involuntariness and external motivation, leading to negative correlations with positive outcomes. In contrast, harmonious passion integrates into one's life and is driven by intrinsic motivation, resulting in beneficial effects, such as enhanced deliberate practice. The insight emphasizes the importance of pursuing passion in a way that feels voluntary, suggesting that true grit and high performance stem from harmonious passion rather than an involuntary obsession.