It is a profession where the old school tie or friendships forged on the football field can make or break careers.

Now the Law Council of Australia is launching a national campaign to help counter unconscious bias among lawyers.

A program of workshops and online courses will be rolled out in barristers' chambers and law firms across the country to help open lawyers' eyes to their own biases, including gender bias.

"Human beings are hard-wired in our brains to recognise difference," said Law Council of Australia president Fiona McLeod, SC.

"When somebody walks into a room you within a millisecond recognise the gender of the person, the race of a person and any distinguishing physical characteristics."

Annette Hughes, a consultant to law firm Corrs Chambers Westgarth, said the human brain made decisions based on unconscious biases "faster than it can be detected".

She said affinity bias, where leaders naturally chose to surround themselves with people who reminded them of themselves, had "a lot of pejorative names – the good old boys' club, locker room mentality".

"It comes down to people [being] more comfortable when they're surrounded by people who think like them because it reinforces that their judgments are right and their behaviours are right," Ms Hughes said.

She said "many of us, male and female, have an unconscious bias that associates male with leader and female with home".

"It affects decision-making by making us favour males for promotion and raises ... over females without realising that our unconscious bias is operating to make that happen."

She said the best way to counter unconscious bias was to "slow your thinking down" and apply clear criteria to decision-making.

The hour-long online training module, which will be available from next month, includes scenarios to help lawyers detect and avoid bias.

The profession is dominated by men from an Anglo-Saxon background and the training module helps identify bias on a range of grounds, including race and gender.

Corrs started unconscious bias training more than five years ago and was very supportive of the program, Ms Hughes said.

Women now make up more than half of law graduates but account for about 22 per cent of practising barristers in NSW and 8 per cent of silks.

In Victoria, the figures are slightly higher, at 28 per cent and 13 per cent respectively.

Ms McLeod, an accomplished silk, said she was "stunned" to discover in online tests that she also "associated women with family and men with the workplace".

"That's just my programming," she said. "I don't have to act on that if I'm consciously aware if that's what my programming is.

"Diversity is what supports the best decision-making."

Ms McLeod said the program was open to all lawyers but the main focus was decision-makers.

It is one of a series of major diversity projects initiated by the Law Council.

Last year it unveiled an equitable briefing policy that set a national target aiming for women barristers to be briefed in at least 30 per cent of all matters and be paid 30 per cent of all brief fees by 2020.