The Tsundoku of Human Relationships
How unread books mirror our unengaged connections — and what that means for leadership
In both our personal and professional lives, we often surround ourselves with people just as we surround ourselves with books. Some are beloved favourites we return to again and again. Some were meaningful for a season. And some — though added with sincere intent — quietly gather dust on the shelf. We think of them fondly, but we don’t actually engage. They become a kind of relational tsundoku: people we intend to “read” one day, but haven’t yet.
Tsundoku (積ん読) is the gentle, hopeful habit of collecting books faster than we can read them. Recently, away from the daily demands of school leadership, I began working through some of the unread titles I’d accumulated over the years. It reminded me of the many offices I’ve occupied — each lined with shelves of books I meant to get to “someday.” There was always that one title I kept promising myself I’d eventually read. That quiet optimism seemed to follow me from place to place — a personal echo of lifelong tsundoku.
People can become like those unread books. We scroll through our contacts or social media feeds and see names from different chapters of our lives — reminders of who we were, and how we’ve changed. We stay connected in theory, not in practice.
This is where Robin Dunbar’s research offers clarity. In his book Friends: Understanding the Power of Our Most Important Relationships, Dunbar observes:
“There seems to be a cognitive limit to the number of individuals with whom any one person can maintain stable relationships.”
That number — famously known as Dunbar’s Number — hovers around 150. It’s not an exact cut-off, but a reminder of our cognitive and emotional bandwidth. Across cultures, these relationships naturally form in layers: 5 intimate connections, 15 close friends, 50 friends, 150 meaningful contacts.
Even in the age of endless digital connection, this pattern holds. We may accumulate thousands of followers or contacts, but our ability to invest in them meaningfully remains unchanged. Without regular interaction, relationships drift outward — not necessarily from neglect, but from natural limitation. This invites important questions:
How do we keep people from quietly slipping into our relational pile?
How do we respectfully allow others to move outward — without guilt or regret?
As leaders, we are often tempted to maintain meaningful relationships with everyone — to be available, present, and emotionally invested at all levels of an organisation. But the truth is, leadership follows the same human patterns Dunbar describes. We are not exempt from the limits of time, attention, or emotional bandwidth. Pretending we can lead 150 people with equal depth is a kind of professional tsundoku: accumulating connections we can’t fully engage, holding onto every initiative and interaction with the hope we’ll get to it “someday.”
But the most effective leaders aren’t those who try to do everything for everyone. They are those who curate intentionally — investing deeply where trust and alignment matter most.
This is especially true in the inner layers of a team or community. The relationships that sit closest to the centre — the 5s and 15s — require something more than visibility or communication. They are built on the principles of partnership: open communication, shared stories, reciprocal trust, and aligned goals. These are not soft skills — they are the architecture of resilient teams and thriving organisations. But they can only exist where there is time, presence, and emotional investment. They cannot be mass-produced. They must be cultivated, person by person.
Leaders who understand this build smaller communities within larger systems. They focus not on scaling relationships, but on deepening them. They know that clarity, trust, and alignment flow outward from these core connections, shaping the culture as a whole.
And just as with books, not every relationship is meant to stay open on the desk. Some are meant to be returned to often. Others belong to a finished chapter. The art of leadership — and of life — is in knowing the difference. It’s in curating with care, nurturing what’s vital, and letting go with care. When we do, our relationships — and our leadership — become defined not by accumulation, but by depth, purpose, and connection.
Relationships, like books, shape our thinking, leadership, and sense of belonging. When we curate intentionally — nurturing the meaningful, releasing what no longer fits, letting go with respect, and revisiting what deserves rediscovery — we build communities defined not by accumulation, but by depth, purpose, and shared sense of belonging.