Chapter one, paragraph one. That’s how long it took for Tiffany to see herself in Adult Children of Emotionally Immature Parents. She’d spotted psychologist Dr Lindsay C Gibson’s book in her therapist’s office and felt drawn to the title alone.
Her hunch wasn’t wrong. In the opening pages, Gibson put words to a feeling Tiffany had carried through her entire life, ever since she was eight years old and her mother told her: “I need you to be strong for us.”
Tiffany’s mother had just learned that her father, Tiffany’s grandfather, had died, and she had broken down. “She screamed and fell on the floor crying … I just thought my mum was dying,” she says. “I’d never seen an adult fall apart like that.”
Now 42, and based in western US, Tiffany remembers the moment as life-changing. Her own father had died only six months beforehand. “I think I knew I wasn’t supposed to be strong for my mum, but she was always fragile.”
Reading Gibson’s book decades later in 2023, Tiffany finally felt validated in her childhood impression that her mother was somehow “not a grownup”. She also saw herself in Gibson’s description of the effects of being raised by such an “emotionally immature” parent, such as compulsive self-reliance. Growing up, Tiffany had learned to hide her problems from her mother, because “often she’d just make things worse”.
Tiffany says Gibson joined the dots between this and her difficulties, in adulthood, with intimate relationships and asking for help. “The book gave words to experiences I’d had, and validated that I’m not crazy: this is a normal response to growing up with a parent like that.” A therapist herself, she has since recommended the book to a hundred-odd clients and friends. “What I usually tell people is, ‘if the title makes sense at all, read the book.’”
First published in 2015, Adult Children of Emotionally Immature Parents has become a somewhat unlikely slow-burn global bestseller, recently surpassing a million sales. The book’s reputation has grown steadily since 2020, in step with the interests of an increasingly therapised, self-reflective younger generations. On TikTok and Instagram, it’s gained its own shorthand (“ACEIP”) as people flip through their heavily highlighted copies, read passages aloud and summarise the key takeaways.
Gibson was not surprised when ACEIP began recirculating, she tells me when we speak on a video call. “It made sense that people were responding to it so strongly because I had seen how well it worked in my therapy patients.” Her primary feeling was relief: “Thank goodness that this is reaching its audience.”
In conversation, Gibson presents as the sort of therapist you’d feel lucky to find: she is a careful listener, quick to call attention to nuance without ever being dismissive of individual experience, and radiates intelligent compassion.
She is speaking from her home in coastal Virginia where she has been in private practice for more than 35 years. Recently, though, she’s taken on fewer patients to make time for writing. After Adult Children of Emotionally Immature Parents, Gibson published several follow-up titles, all helping people to break free from such parents.
‘Just treat your child as you would a cherished friend’: Advice from psychologist Dr Lindsay C
Now she is seeking to tackle the problem at the source with her next book, How to Raise an Emotionally Mature Child, due to be published in April 2026. Writing it was a full-circle moment, she tells me. “I came back to, ‘What is the absolutely most essential thing we can do to prevent the suffering that comes from emotional immaturity through the generations?’ And that’s a book on raising children,” she says.
The core (and, to some, controversial) tenet of Gibson’s work is that parents are “not necessarily more mature than their children”. Many simply aren’t fully emotionally developed, which blinds them to their children’s needs. Though these parents are typically egocentric, inconsistent and unavailable, Gibson identifies four distinct though sometimes commingled types.
There are those, like Tiffany’s mother, who are explosively emotional, “run by their feelings” and who lean on their children for stability. Others are driven perfectionists and compulsively over-committed, inclined to attempt to control their children without giving them real time or care. Conversely, passive parents avoid engaging with emotional turmoil and turn a blind eye to issues including even neglect. Finally, Gibson describes “rejecting parents” who resent being bothered by their children, have zero tolerance or empathy for others’ needs, and otherwise “make you wonder why they have a family in the first place”.
For children, the effects of this emotional neglect and isolation can be enduring and severe, Gibson says. They struggle to trust themselves, form healthy relationships or otherwise thrive in later life. Many go on to develop anxiety or depression. Gibson came to write Adult Children of Emotionally Immature Parents after observing the effect on children.
About 15 years into her private practice, in the late 1990s, she began noticing that patients she experienced as intelligent, moral, kind and lovable had “a degree of self-doubt and bad feeling about themselves that, to me, seemed very distorted and extreme”. Over time, Gibson consistently identified the root of the hurt in her patients’ childhoods. She was struck by “a sense of injustice”, she recalls, still indignant, the feeling that “this is not right … The wrong people are in therapy”.
She landed on the “emotional immaturity” framing around the mid-2000s. By drawing on her training in childhood development and professional experience of evaluating patients against established age markers, Gibson “could peg where [these parents had] developed up to and stopped”.
“I could say, ‘this person’s ability to regulate their emotions, their sense of self, their ability to think of other people’ are all more like that of a four to five-year-old than they are of a 45-year-old.’”
That frequently proved “transformative” for her patients, Gibson says, enabling them to recontextualise their parents’ behaviour and lessening the weight of painful experiences. “They could see that the dad’s tantrums were not the mightiness of a supreme authority figure; they were the loss of emotional control of a very small child who’s not getting what they want … You can see how that shrinks the fear and intimidation.”
Most such parents are not knowingly malicious or neglectful, but rather a product of their own times and upbringings, Gibson says. By recasting their parents as lacking skills and abilities they may never have had a chance to develop, Gibson found many of her patients were able to make peace with their past, and in some cases improve the relationship. Once people feel their version of events is validated, Gibson says, they may cast off roles or expectations they have shouldered since childhood and free themselves of toxic family dynamics.
Many describe reading the book as transformative. Will Watson, 44, had to take a few weeks to process the opening chapters. “It really just hit me so hard,” he says by phone from Vancouver. “I remember thinking something that I’ve since heard from so many people: ‘How did she know?’”
Watson played a part in the pandemic-era resurgence of Adult Children of Emotionally Immature Parents, featuring it on his Instagram account, Academy of Self-Help. He set the profile up in 2020 to share useful morsels he’d gleaned from his personal reading; today it has nearly 80,000 followers. “I thought, if this is helping me so much, it could help others.”
The passages he shared from Gibson’s book “exploded” on social media, Watson says, travelling far beyond his usual audience. The response from users was “a lot of ‘Wow, this is me!’ and ‘I see you’ve met my mum’ – both joking, but identifying with something deeper.”
Now concepts once confined to psychology clinics, such as boundaries and attachment theory, are in colloquial use, and more people are interrogating their past, often earlier in life
After Watson contacted Gibson to let her know about the reaction, they collaborated on an online course. The debt he feels to her is obvious. “She’s the most validating and generous person I’ve ever met,” Watson says.
The recent resurgence of Adult Children of Emotionally Immature Parents has been attributed to younger readers discovering it on social media. It reflects the mainstreaming of therapy over the past decade, driven by increased awareness of mental health and trauma, and a culture more comfortable with personal sharing. Now concepts once confined to psychology clinics, such as boundaries and attachment theory, are in colloquial use, and more people are interrogating their past, often earlier in life. The result is that parents, and experiences of being parented, are increasingly under scrutiny. For some individuals, such reflection can be beneficial; for families as a whole, it can create tensions, triggering generational differences over mental health.
The stakes are much higher than dinner-table harmony, as the widely reported movement of younger people going “no contact” with their parents suggests. Joshua Coleman, a clinical psychologist, writes in Rules of Estrangement: Why Adult Children Cut Ties and How to Heal the Conflict that the trend is partly driven by “changing notions of what constitutes harmful, abusive, traumatising or neglectful behaviour”.
In her book, Gibson encourages the reader to judge for themselves the harm done by their parents, as well as “what level of relationship might be possible”. Her aim is to validate their experience, alleviate the bad feeling and burden, and help them reach “more realistic expectations” of their parents.
But as much as her book has resonated, it has also been criticised as overly simplistic and lacking compassion for “emotionally immature” parents’ experiences. In February, retired psychologist Jane Turner Goldsmith wrote that Gibson bundles together a wide range of different behaviours, some manifestly destructive; others “just annoying”.
The New York Times’s David Marchese likewise expressed scepticism in an interview with Gibson earlier this year, arguing that the label was reductive and could be weaponised against otherwise well-intentioned parents, worsening family dynamics.
“Emotional immaturity” is not a recognised mental disorder and is indeed a broad definition – but, Gibson says, that’s partly why her patients and readers have found it so helpful. It’s also more productive than attempting an armchair diagnosis to explain their parent’s behaviour. “Emotional immaturity is much more palatable, I think, and kinder than saying, ‘your dad’s a raving narcissist’ or ‘your mum’s got borderline personality disorder,’” Gibson says.
She is conscious that the label of “emotionally immature” could be perceived as equally pejorative, and create distance between children and parents. But, to Gibson, anger, resentment and rumination are often part of healing or alleviating painful family dynamics. “Whether or not people can progress from the resentment stage, is different for different people.”
Her response to clients wanting to go “no contact” with their parents is to “take a healthy break” instead. With time and further reflection, Gibson says, they may find they are able to come back with a more understanding and open attitude towards the relationship. But, she adds, “it can be a very bumpy road, especially if both parties are not invested in self-reflection or improving things”.
Gibson is now applying herself to the other end of the relationship. How to Raise an Emotionally Mature Child gives accessible advice and strategies, grounded in basic child development and psychological concepts. “The idea is this is not arcane, esoteric knowledge that can only be accessed through therapy,” she says.
Indeed, her top parenting tip might seem revelatory even to people whose parents weren’t especially emotionally immature. “It’s actually very simple: just treat your child as you would a cherished friend,” Gibson says. As a parenting mindset this supports “a genuine relationship”, recognising the child’s individuality, humanity and psychological complexity.
She is cheered by the efforts of modern parents to engage with their children’s emotional wellbeing and development. “You can see the consciousness there and that, to me, is a fantastic psychological development for humanity.” Older parents whose adult children are questioning their experiences in therapy, or touting the wisdom of Adult Children of Emotionally Immature Parents, might feel more ambivalent. Gibson’s advice to them is to do their best to not take it personally, or centre themselves in any discussion.
“Sometimes, understandably, the parent is so afraid of not having their child’s love and approval that they get very defensive,” she says. “It would be so much more helpful if they said, ‘really? That’s not the way I see it at all, but I’m so curious and concerned … Tell me what you’re talking about; I want to understand’.” After all, Gibson says, that’s the response we’d want from a friend.
How to Raise an Emotionally Mature Child: Your Blueprint to a Lifetime of Happiness and Success for Your Child by Lindsay C Gibson will be published by Ebury in April 2026. Order a copy at The Observer Shop for £15.99. Delivery charges may apply
Photographs by Guasor/Getty Images, Boom