Harvard Business School Professor on Building Trust, Reducing Regret, and the Underrated Power of Oversharing | Leslie John

What It Covers

Harvard Business School professor Leslie John presents research showing that under-sharing, not oversharing, poses the greater risk to health, relationships, and career. Drawing on neuroscience, behavioral studies, and personal experience, John outlines why self-disclosure builds trust, reduces physiological stress, and prevents the rumination and resentment that silence creates.

Key Questions Answered

• •The Hider Penalty: In studies with thousands of participants, people consistently preferred someone who disclosed the worst possible information—prior STDs, poor grades—over someone who simply refused to answer. Eighty-nine percent chose the revealer when making hiring decisions. Withholding creates distrust so severe that silence is perceived as worse than the most damaging confession, making transparency a strategic advantage in relationships and professional contexts.
• •Disclosure's Physiological Reward: Neuroscience research shows that self-disclosure activates the same brain pleasure centers as sex, making it intrinsically motivating. Separately, a study of preschoolers found that children who expressed emotions facially showed lower galvanic skin response stress levels. By kindergarten, boys had learned to suppress expression and became measurably more physiologically stressed, demonstrating that cultural stoicism carries a real biological cost.
• •Putting Feelings Into Words: Writing or speaking about worries engages the prefrontal cortex, imposing logical structure on circular thoughts. This transforms swirling anxiety into a narrative with a beginning, middle, and end, converting uncertainty—a primary anxiety driver—into concrete, manageable information. The effect works even in private journaling; James Pennebaker's randomized HIV studies showed measurable immune health improvements in participants who wrote about their thoughts and feelings.
• •The Validation Hierarchy: When someone vents, the single most effective response is validation—saying "I hear you, that sounds hard"—without needing to agree or solve anything. Research testing multiple response types found "this too shall pass" outperformed perspective-taking and positive reframing. Simple acknowledgment, including the phrase "that sucks," reduces rumination and increases well-being more than advice, problem-solving, or attempts to find a silver lining.
• •The One-Layer-Deeper Rule: Rather than calculating exact disclosure thresholds, default to sharing one level deeper than feels comfortable. In small talk, move from describing observable events to stating what they mean personally, then ask the other person a reciprocal question. Studies on leader introductions show admitting nervousness about public speaking—even mentioning a dry mouth—still registers as competent and builds trust; only disclosing full panic attacks crossed into competence-undermining territory.
• •The Ben Franklin Decision Matrix: Most people only evaluate the risks of speaking up, then stop. A four-quadrant framework forces consideration of all factors: risks of revealing, benefits of revealing, costs of staying silent, and benefits of staying silent. The costs of silence—rumination, resentment, passive aggression, self-loathing, missed professional credit—consistently outweigh anticipated social risks. Cornell psychologist Tom Gilovich found seventy-six percent of life regrets involve inaction, and palliative care research lists "I wish I had shared my feelings more" as the third most common deathbed regret.