In it, Clance and Imes proposed that professional women, no matter how accomplished, continued to believe deep down inside that they were and always had been 'faking it' and would soon be unmasked as the impostors that they were. For my generation, which came along after theirs, it is still true. You can't grow up hearing tens of thousands of sentences over the years that begin with "Girls can't. . ." or "Women don't. . ." without coming to believe in your heart of hearts that whatever it is you are doing now, you really shouldn't--and indeed, can't.
In the published paper, the authors described a self-perpetuating cycle in which, because women attribute their successes to luck or other temporary outside forces, they are unable to internalize any success as proof of their very real abilities. So no amount of success can convince them otherwise: Each new level reached in their careers is a mistake and only brings new pressures and fears of being unmasked. Indeed, many of us who read the draft back then were convinced it didn't apply to us because we really were impostors.
This may be in part motivated by the adaptive function such a belief in one's own ineptitude serves: If a woman is not really successful or smart, then she gets to keep her femininity. She's not really a threat to the men in her work group/profession/family. It is the obverse side of sexual discrimination that society "rewards" women (in a manner of speaking) who live out the feminine stereotype, just as it punishes women who do not. Look at the recent flap over Barbara Boxer wanting to be called by her correct courtesty title--not "ma'am", but "Senator." Little girls observe this very early and adjust their behaviors accordingly.
In 1985, Clance published a book about it:
As for younger generations, I suspect it might still be true at least to some degree. I had a little kid in a session about 20 years ago who wanted to play with those little metal cars and trucks. He was divvying up toy vehicles for us to "drive," and commented that "Girls can't drive dump trucks." He kept that one for himself and gave me a sedan. Women could and did, even then, but it was just not part of his world view. Oddly, this post-Second-Wave child, raised by parents of my generation, was perfectly comfortable with the concept of women astronauts, having seen Sally Ride on the TV--just not women truck drivers. His generation is old enough to be raising kids of their own now. Wanna bet what they're probably teaching them?
But I digress.
Clance and Imes, supposedly feminists, totally missed the root cause of the phenomenon, locating its origins in one of two family dynamics, despite their recognition that it is gendered. Based on their explanation, there would be no reason to expect any more women than men to have the problem. Yet, as the authors recognize, research into attribution theory shows that women by the age of ten are habitually explaining their successes and failures differently than boys. It cannot be coincidence that in a patriarchal society little boys claim credit for their successes, while girls do not.
If Clance and Imes are wrong about the etiology, can they be right about the intervention? Probably not, since if the problem is located at a societal level, then an intra-personal, individual intervention hardly addresses it. Possibly so since, on the other hand, psychologists as agents of change often must start with the individual before us. Clance and Imes begin by recommending group, with which I heartily agree. People can see things in others that they cannot in themselves, and thus group becomes an ideal setting in which women can confront each other's unrealistic self-images. The authors recommend cognitive-behavioral techniques, such has having a woman practice different expectations or eliminate behaviors like compulsive work habits that reinforce the cycle. And they recommend role-playing both sides of a conversation in which she is alternately telling people she's brilliant or telling them that she's really an idiot but has had them all fooled. These are all great as far as they go, but I believe that if a woman is not consciously aware of how her "problem" functions in a social context, she won't be able to hang onto the changes she makes in the protected arena of therapy.
A therapy group is but a tiny raft in a sea of bigotry. If the raft's occupants don't understand the environment in which they are adrift and their relationship to it, they will not survive. Consequently, in my work I believe that it is of core importance that women come to see this as a gendered, social issue. The family is only the agent of society in socializing girls to be women. It is vital that women understand that men, and other women co-opted by patriarchy, will not be comfortable with their new comfort in their own skins and will work to return things to status quo ante. If they don't know this, they won't be prepared to protect their gains in personal growth.
Clance, P. R. & Imes, S. A. (1978). The impostor phenomenon in high achieving women: Dynamics and therapeutic intervention. Psychotherapy: Theory, Research and practice (15), 241-