When given the choice, people prefer to collaborate on work projects with higher-paid colleagues, but they want to hire subordinates with a lower pay history than theirs, according to research published in the journal American Psychologist.

The research aimed to explore how a trend toward increasing pay transparency in the business world may affect workers’ behavior.

“I’ve long been interested in the ways in which slight—and not-so-slight—differences in salaries can generate strong reactions from people,” said Kevin Kniffin, Ph.D., an assistant professor at Cornell University and co-author of the study.

“When combined with the trend toward more pay transparency in organizations, whether required by law or crowdsourced by employees, and the trend toward more teamwork and collaboration in work, it’s increasingly valuable to understand more about how people think about pay differences in relation to co-workers and potential collaborators.”

Some researchers have hypothesized that pay transparency could cause workers to resent—and avoid working with—higher-paid colleagues. But Kniffin and his colleague Angus Hildreth, Ph.D., suspected that might not be the case, and that instead people might use pay as a signal to decide which co-workers were most competent.

To explore that question, they conducted three experiments in which they gave participants hypothetical information about colleagues’ salaries and asked them whom they would prefer to work with on a project.

In the first experiment, they gave 171 economics Ph.D. students a hypothetical situation in which the students could bid to work on a project and could choose a partner to work with, knowing their potential partners’ bids as well. Nearly two-thirds (65%) requested to work with the person who asked for the higher salary.

In the second experiment, 171 online participants faced a similar scenario in which they could choose to work with a higher-paid or lower-paid colleague.

At first, nearly three-quarters (73%) of participants chose to work with the higher-paid colleague. However, the researchers then gave the participants additional information that both colleagues had the same knowledge, skills, abilities and experience as the participant. After that, the percentage of participants who preferred to work with the higher-paid colleague was significantly smaller, dropping to 60%.

In a third experiment, 375 online participants were asked to name four real-life colleagues, two of whom they had worked with before and two of whom they had not. Then the participants were asked to imagine that one of each pair had a higher salary than their own, and one of each pair had a lower salary.

Again, when asked to choose a project partner, the majority of participants chose the colleague with the higher salary. However, the difference was less than in the purely hypothetical experiments—in this case, when participants were choosing between two colleagues they’d worked with before, 58% chose the higher-paid colleague.

“People seem to assume that higher pay is merited and reflects greater competence. And they seem to assume that collaborating with someone with higher pay will be beneficial—in other words, that the higher-paid coworker will share some of their greater knowledge and skills with them,” Hildreth said.

Finally, in a fourth experiment, the researchers looked at how pay history affected people’s hiring decisions. They asked 138 online participants, all with hiring experience, to choose between two job candidates with the same knowledge, skills and experience.

All else being equal, 71% of participants preferred to hire a candidate with a salary history lower than their own. This may reflect a belief that salary differences should correspond to organizational rank, according to the researchers.

Overall, the research has implications for workplaces as pay transparency increases, according to Kniffin.

“While companies may anticipate pay transparency would impede employees’ willingness to work with higher-paid colleagues, we find evidence that salary disparities can actually function as a magnet for collaboration,” he said.

Future research could examine how these teaming decisions play out in the real world, according to Hildreth. “I’m intrigued by whether people actually benefit from collaborating with their higher-paid peers and whether higher-paid workers do share their assumed greater skills,” he said.

Apple Inc. has been warned by the European Union to open up its highly guarded iPhone and iPad operating systems to rival technologies, or eventually risk significant fines under its flagship digital antitrust rules.

EU watchdogs announced under the bloc’s Digital Markets Act that Apple must step into line with strict new laws on making operating systems fully functional with other technologies. The Brussels-based authority gave the company six months to comply, or face the threat of future penalties.

While the announcement is a step shy of being a formal investigation, the EU aims to compel Apple to re-engineer its services to allow rival companies to access the iPhone’s and iPad operating systems.

“Today is the first time we use specification proceedings under the DMA to guide Apple towards effective compliance with its interoperability obligations,” EU competition chief Margrethe Vestager said in a statement. “Effective interoperability, for example with smartphones and their operating systems, plays an important role in this.”

Cupertino, California-based Apple said it’s created ways for developers to request additional interoperability with iPhone and iPad operating systems, while protecting users’ security. Undermining protections built into its systems over time would put European consumers at risk, the company added.

Apple shares rose 1.6% to $224.25 in premarket trading of 164,801 shares. The EU announcement confirms an earlier report by Bloomberg.

One of the aims of the DMA is to ensure that other developers can gain access to key Apple features, such as its Siri voice commands and its payments chip.

The EU may later decide to launch a formal probe if Apple doesn’t step into line with the DMA, which could eventually lead to hefty fines of up to 10% of global annual sales. It is already facing a parallel investigation into its App Store rules for developers, which could also lead to hefty penalties.

Earlier this month, Apple announced the latest version of its flagship device, the iPhone 16, betting it can entice consumers with modest hardware upgrades and AI technology that’s still on the horizon.

But in June, the U.S. giant said that certain features—including Apple Intelligence, iPhone Mirroring and SharePlay Screen Sharing—would be held back from the EU, due to the DMA’s requirements on operating systems to work with third-party apps.

2024 Bloomberg L.P. Distributed by Tribune Content Agency, LLC.