In any relationship, when you reveal something vulnerable about yourself, about your life, the other person typically does the same. Maybe they don’t do it in the same conversation, but over time, they share personal, private information, too. Or, if they don’t, you likely know a lot about the person you reveal your heart to — or, at the very least, you know their age, their family situation, where they live, what they like.

And yet, you rarely know much, if anything, about the one person you tell everything to or share something you’ve never shared before: your therapist.

Why is that? Why do therapists stay mum about so many details of their lives, even superficial things like their age and marital status?

For starters, this tradition of little to no self-disclosure goes back to Sigmund Freud and classic psychoanalysis. Freud proposed that the more a therapist presents themselves as a “blank slate” in session, the easier it is for clients to transfer their conflicted feelings about their caregivers onto the clinician—which they can then further explore, said Ryan Howes, Ph.D, a psychologist in Pasadena, Calif. For instance, a client assumes their clinician is just like their absent mother or controlling father or judgmental teacher, he said.

Most of Howes’s clients have transferred feelings and identities onto him, perceiving him as everything from a loving grandmother to a critical brother to a distant God. Howes keeps self-disclosure to a minimum but disagrees with Freud’s insistence on being a blank slate: “I’ve just found that becoming a blank slate does not expedite this process at all. If they’re going to see me as a conniving uncle, they’re going to do this whether or not they know details about my life. So I can be me, and their transference will come regardless.”

Like many therapists, Howes also doesn’t reveal much about himself because clients are paying him to work on their issues—and he doesn’t want to waste their time and money talking about his own life.

As he said, “You don’t examine your dentist’s teeth, do you? Of course not, the focus is on you and your concerns.”

Self-disclosure also can be a safety issue. Most people seeking therapy can be trusted with personal information. But some cannot—and therapists aren’t always able to tell the difference. “It takes years of training, vetting, supervision, and licensing exams to become a therapist, and sometimes even then some unscrupulous characters slip between the cracks,” Howes said. “It takes none of this to be a client, so many therapists would rather be safe than sorry.”

Manhattan therapist Panthea Saidipour, LCSW, pointed out that all therapists are different. How much a therapist reveals about themselves really depends on the theories that guide their work and their relationship with each client, she said.

Saidipour says very little about her personal life. She takes a similar stance as Howes: “It’s just that it’s your time and I’m way more interested in helping you say what’s on your mind.”

However, she noted, it’s perfectly normal to be curious about your therapist, so she welcomes all questions. She may or may not answer them. But she will focus on understanding why you’re asking them.

Katrina Taylor, LMFT, a therapist in private practice in Austin, Texas, is interested in the same thing. She believes that the questions clients ask reveal something about them that is ripe for exploration. “If a client wants to know a therapist’s age or marital status or political affiliation we explore what it means for them to know that…For example, I’d explore what fantasies a client has about my age, what feelings come up. Do they wish they had accomplished something if they are that age? Is there grief if they feel time has passed them by? Is there envy of a therapist’s youth or wisdom?”

Howes believes that some self-disclosure is key, because it creates a stronger relationship between client and clinician. For instance, if a client tells him a story about losing a loved one, he might share that he, too, has grieved similar losses in his past and understands how it feels.

Psychologist Matt Varnell, Ph.D, encourages clients to ask him questions about his life, because what they’re often trying to figure out is how deeply they can trust him. For instance, he commonly gets asked if he’s ever lost a loved one, has kids or has gone to therapy himself.

“Personal questions are another way of asking: ‘Have you grown from your suffering so that I can trust you enough to grow from my own?’” said Varnell, who practices at The Center for Psychological and Family Services in the Chapel Hill, North Carolina area.

No question is off limits, he said. But “there are many questions I won’t answer or at least [not] as clients would like me to.”

When you’re working so closely with someone, it’s understandable that you’d be curious about them. And you might feel frustrated that your therapist barely reveals anything about themselves. But the focus in therapy is on you. And you might even ask yourself: Why am I really so curious about that? and bring it up in therapy. Because exploring these kinds of thoughts can spark profound insights—which is what therapy is all about.