06/03/2015 04:52 EDT | Updated 06/03/2016 05:59 EDT

'The Confidence Code' aims to silence feelings of self-doubt hindering women

TORONTO - A book exploring the need for women to channel and boost their confidence proved eye-opening for co-author Claire Shipman — especially when she turned a critical lens on herself.

"One of the most valuable things for me in all the research is the impact it's had on my parenting. I have really realized that it's so important for kids to fail and to have struggles," said Shipman, mother to son Hugo, 13, and daughter Della, 10.

"I think as a perfectionist and then a helicopter-ish parent ... I fall into the trap of: 'Let me just make things easy for them' or 'I want to fix things' or 'I want them to go well.'"

In the bestseller "The Confidence Code: The Science and Art of Self-Assurance — What Women Should Know" (Harper Business), Shipman and co-author Katty Kay explore why even the most accomplished, educated and skilled women are often plagued by a lack of self-belief.

The Washington, D.C.-based journalists also seek to define the concept of confidence and investigate the nature and nurture factors at play.

Anecdotes and research reveal a reluctance among many women to seize opportunities for advancement.

A Hewlett-Packard study aimed at determining how to draw more women into top management found the company's female employees only applied for promotions when they believed they met 100 per cent of the qualifications. Meanwhile, the men were "happy to apply" when they thought they could meet 60 per cent of the job requirements.

Other studies found female business school students negotiated for significantly less in salary compared to their male counterparts.

Even female global leaders aren't immune to self-doubt.

"The Confidence Code" features an interview with Christine Lagarde, managing director of the International Monetary Fund. She confessed to moments where she needed to "go deep inside" as a way to reassure herself of her strength, confidence and abilities.

Lagarde also admitted she overprepares — a habit she realized she shared with German Chancellor Angela Merkel after a discussion they had.

"What we as a society do without even realizing it is we encourage the perfectionistic instinct in girls," said Shipman, a contributor to ABC News show "Good Morning America."

"I don't think anymore we're sending girls messages (that) 'You can't be president. You can't be a doctor....' No girl thinks those doors are closed anymore.

"But it's just the kind of behaviour we encourage in terms of achievement that doesn't always serve them as well as ... (in) learning to fail and losing."

Shipman recently spoke in Brazil and found the ruminating, over-thinking and perfectionistic tendencies displayed by women transcend borders.

"I'm not sure if our brains have worked that way forever and ever, or over time they've evolved," Shipman said while in Toronto. "But there's something about the way they work that makes us more hyper-aware of what's possible, what's right, what's wrong, what the landscape looks like, the measure of everything.

"We see all that and factor it in and we're constantly processing it in a way that men aren't."

As a self-confessed "master perfectionist" and "ruminator," Shipman said she has worked to create new habits, like not overthinking about someone's reaction to an email.

While the book encourages women to remind themselves of their abilities and achievements when self-doubt creeps in, Shipman said support networks are also key.

"The research shows for women, we often won't act unless we have one person we respect saying: 'Oh, you could win that seat. You could run for office. I could see you doing that. So for women to understand the power they have even with their friends ... I think that's very important.

"But not just (saying): 'You're great.' (It's) the power of encouraging us to take risks, encouraging us to do what seems uncomfortable."

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