In a report just this past year, nearly a decade after the crisis, the Group of Thirty offered this sobering assessment of where the industry stands: "Banking is, in 2015, at a low point in terms of customer trust, reputation, and economic returns."

It is not hard to see how such an outlook materialized. Banks have continued to fight reputational problems since the 2008 meltdown, from scandals over mortgage servicing and the rigging of Libor and foreign exchange rates, to more enforcement actions tied to lax anti-money laundering and sanctions violations.

But there are now signs that big banks are finally getting the message about the need for a cultural transformation. Indeed history may judge 2015 as the year banking turned a corner on culture.

After a lengthy period of bankers trying to put the crisis behind them, a new generation of chief executives at large institutions is emerging — leaders who will be less colorful, less controversial and less swashbuckling than their predecessors. They will be judged not for their aggressiveness or short-term gains but for their steady stewardship of their institutions on behalf of clients, shareholders and employees.

In 2015 alone, several major banks named new chief executives who either came from less volatile businesses or stated their intention to change the culture at their financial institution.

For example, Standard Chartered's new CEO, William T. Winters, most recently ran an asset management company and worked with the Independent Commission on Banking in Britain, whose recommendation to "ring fence" retail banking from investment banking became law. James E. Staley, the new CEO of Barclay's, said he intends to continue to shrink the company's investment banking operation, establish a collaborative relationship with regulators and complete a cultural shift for the institution.

A number of leading banks are already well along in redefining their business models. Morgan Stanley, UBS and Credit Suisse have rebalanced their portfolio of business lines, expanding in stable annuity-fee paying businesses like wealth management while contracting in more volatile businesses like investment banking. Certainly, banks are being driven, in part, by regulatory changes, but the leaders of these banks know that for a business model to succeed, their people must believe in it and their cultures must be adapted to it.

Over time, the old measures of success will likely give way more and more to a set of metrics more suited to this kind of stewardship. Organizations will promote and financially reward individuals who can generate stable, sustainable profits over the medium to long term, rather than the short term. Such profits will depend on sustained positive relationships with clients, whether they are institutional investors, corporate clients or consumers.

Career success will be measured in terms of promotions and financial reward accrued over a number of years versus marking-to-market on an annual basis. We are already seeing this at work in the greater percentages of deferred compensation, financial clawbacks and bonuses governed by multi-year versus single-year outcomes.

But by far the leading indicator of progress is the direct hand that boards are increasingly taking in culture. Culture has become a high priority for directors, and they say it will be a long-term project, not just point-in-time changes. Such transformation requires total commitment from the board down to the most junior employee. It involves identifying, communicating and reinforcing the values that underpin the desired culture, measuring the degree to which businesses and individuals live these values, and holding people accountable through performance management and compensation.

We might look back at 2015 as the watershed year for bank culture. Appointing stewards as chief executives is only the beginning.

Daniel Edwards is global managing partner of the private equity practice at Heidrick & Struggles, based in the firm's Washington office. The views expressed are his own.