Dear is built on behavioral science, not intuition. Here are the studies that shaped the app.
People consistently underestimate how much others appreciate hearing from them, especially when reaching out "just because."
Across multiple experiments, senders predicted recipients would feel mildly pleased. Recipients actually felt deeply touched. The gap was largest when people hadn't been in contact for a long time.
Liu, P.J., Rim, S., Min, L., & Min, K.E. (2022). Journal of Personality and Social Psychology. doi:10.1037/pspi0000402
This is why Dear exists. The nudge closes the gap between thinking about someone and actually reaching out.
People overestimate how awkward it will feel to reconnect with a lapsed friendship. The anticipatory anxiety is almost always worse than the actual conversation.
Boothby, E.J. & Bohns, V.K. (2021). Journal of Personality and Social Psychology. See also: Harvard Business Review summary
Humans organize relationships in concentric layers: ~5 intimate, ~15 close friends, ~50 active network, ~150 stable contacts. Each layer roughly triples in size.
Dunbar, R.I.M. (2016). Personal Relationships. doi:10.1111/pere.12149
Dear's frequency tiers mirror Dunbar's layers. You set your own rhythm for each person, and the app respects it.
Phone and video calls can maintain the two closest layers of friendship (5 and 15) with similar effectiveness to in-person contact. Text and social media alone cannot.
Dunbar, R.I.M. et al. (2021). Royal Society Open Science. doi:10.1098/rsos.210298
Dear offers text, call, and FaceTime buttons for each nudge. The call and video options exist because the research says they matter.
Specific plans ("I will do X at time Y in place Z") dramatically increase follow-through compared to general intentions ("I should do X").
This is the difference between "I should text my friend more" and Dear showing you a specific person with a one-tap action. The specificity is the mechanism.
Gollwitzer, P.M. (1999). American Psychologist, 54(7), 493-503.
1 in 6 people worldwide are affected by loneliness, which is linked to more than 871,000 deaths a year. The figure comes from the first report of the WHO Commission on Social Connection, published in June 2025.
WHO Commission on Social Connection (2025). who.int
Social isolation increases the risk of premature death by 26%, comparable to smoking 15 cigarettes a day.
Holt-Lunstad, J. et al. (2010). PLOS Medicine. doi:10.1371/journal.pmed.1000316
People with strong social ties were 50% more likely to still be alive at follow-up than those with weak ties.
Holt-Lunstad, J. et al. (2010). Meta-analysis across 148 studies, 308,849 participants. PLOS Medicine. doi:10.1371/journal.pmed.1000316
The single strongest predictor of late-life happiness and health is the quality of close relationships.
Harvard's Grant Study followed 724 people for 85 years. Not wealth, not fame, not achievement. Relationships.
Waldinger, R. & Schulz, M. (2023). The Good Life. adultdevelopmentstudy.org
The average American has 3 close friends, down from 5 in 1990. 15% of men report having no close friends at all, up from 3% in 1990.
Survey Center on American Life (2021). The State of American Friendship
Friendship requires roughly 50 hours to move from acquaintance to casual friend, 90 hours to become a genuine friend, and 200+ hours for a close friendship.
Hall, J.A. (2018). Journal of Social and Personal Relationships. doi:10.1177/0265407518761225
Dear can't create hours together. But it can make sure you don't lose the ones you've already invested in.
Dear is collaborating with researchers to study the impact of gentle nudges on relationship maintenance. If you're a researcher interested in this work, reach out at [email protected].