Families are the survival mechanism of the human species.

Relationships within our families are in constant motion. We are complicated beings, and we experience the emotions that make for peace–and conflict.

Generations clash, even as they remain full of love and compassion.

Siblings fight and come together, fight again, and–with luck—come together for life. Secrets hidden in the depth of a family may rock the boat, but don’t necessarily sink it.

The arrival of grandchildren begins a new cycle. Grandparents are elated, even as they experience the loss of power as their grown kids become parents.

I see myself as a mapmaker, sketching out the routes to conflict and acceptance, to anger and to love.

As our families grow, we change. Our ability to adapt to these changes, and even to experience them with pleasure, keeps us going—and keeps our families alive.

I come from a family of psychologists and psychiatrists, and as an editor I published landmark books in psychology and neuroscience. I worked with generations of psychologists, from Anna Freud to Mary Pipher. And then I felt compelled to write my own books and offer my own insights.

My first grandchild was born the week I got an offer to publish my first book. My writing and my family have grown together. Now there are four grandchildren–and four books.

My goal is to make the turbulence of our ordinary families a little easier to manage. I hope to help us all understand that imperfection is our lot, and so is love. Misunderstandings cannot be avoided, but conversation is a powerful remedy. Like trees in an old forest, our families have roots below the surface. They nurture us, and they sustain us. Our families go back to the beginnings of time and will continue as long as humans inhabit the earth.

I have learned that grandparents have unique gifts for the grandchildren.

We have the time to dawdle with them–perhaps time we couldn’t spend with our own children.

Grandfathers discover a second childhood, where they can be silly as they never were with their own children.

The love in the eyes of a grandchild makes us young again.

And yet we sometimes disagree across generations. Old conflicts reappear. The power we once exerted has passed to the parents of our grandchildren. Time, money, and energy don’t go as far as we would like. We disagree over sweets, presents, and screen time, and then we make peace. Grandchildren grow up and leave us for friends and school. Sometimes they return. Loss and recovery become themes in the lives of grandparents.

Grown children, the parents of the beloveds experience gratitude and resentment. They compete with siblings for time and money. Disagreements about child rearing and adolescent behavior trouble us all. But then we gather together, around a holiday table, at a graduation, or a funeral.

Grandparents are the hinges of history, reaching back to our own grandparents, reaching forward to our grandkids. The century that we hold in our hearts is a gift that travels across generations.