Beyond the Birthday: Why Generational Stereotypes Harm Organisational Culture

In a vast, sunlit library, every book has been rearranged according to the decade it was published.

The shelves no longer speak of poetry, philosophy, business, or fiction; they shout only “1970s,” “1980s,” “1990s.” A dense work of existential philosophy sits awkwardly next to a playful children’s story, both reduced to the era of their first print.

Wanderers in this library find themselves disoriented, searching for meaning but offered only chronology. The stories, once rich and diverse, are hidden behind a thin and misleading label: time.

It sounds absurd, yet many organisations unintentionally do something similar when they sort their people into generational categories.

The intention often feels benign. We are told that Millennials crave purpose; Gen Z needs constant feedback; Baby Boomers resist change. Popular articles and leadership workshops push these ideas with confidence. We take note, hoping for better understanding, better communication, and better management. But the science tells a different story.

As this article is published, I find myself marking another birthday; a fitting moment to reflect on generational perceptions, the psychology of stereotyping, and what research into individual differences truly reveals.

Once more around the sun

Each birthday marks the passage of time for an individual; a reminder that no two journeys are the same. It is not a steady movement along a generational assembly line, but a story as rich and varied as the person themselves.

The story is rooted in both nature and nurture. The combination of our genetics and our environment, learned experiences, exposure, biases, coping mechanisms, conscious decisions and more help those roots grow into the uniqueness that is you. If you had a genetically-identical twin (known as monozygotic), you, your world view and the way you experience that world would still be completely different to your sibling. This is not just through experience and learning. Research into Epigenetics has shown that some genes can be influenced by our environment resulting in variations in stress responses, resistance to disease and personality development (Fraga, 2005; Plomin, 1977).

Age-based generalisations oversimplify the complex weave of values, motivations, and behaviours that individuals bring to work. The very richness we seek to understand is flattened by the assumption that birth year dictates belief or behaviour. But this is no more accurate than being born in early-May guaranteeing to make you reliable, hard-working and loyal, but also stubborn and possessive (I’m a Taurus).

Research consistently finds that there is greater difference within a generation than between generations. If you are a Baby Boomer, you’re more likely to have commonality with a Gen Z’er than with another Baby Boomer.

At first glance, this seems intuitive: if we grew up with similar schooling, media, and work milestones, shouldn’t we share more in common with peers our own age? Yet this is not borne out in the science.

So why do these generational stereotypes persist? Social Identity Theory offers one explanation.

Coined by Henri Tajfel and John Turner in the 1970s, the theory suggests that individuals define themselves by the groups they belong to – their social identities. These group affiliations (such as age, gender, or profession) offer a sense of belonging and self-worth. However, this natural categorisation also brings a shadow side: we tend to exaggerate the differences between groups (the out-groups) and similarities within our own (the in-group). In this context, “Millennials,” “Gen Z,” and “Boomers” become easy categories, and stereotypes emerge as mental shortcuts that reinforce in-group bias and out-group homogeneity (Tajfel & Turner, 1979).

In modern workplaces, when age groups become social categories, individuals may unconsciously prioritise the traits of their “own” group while attributing sweeping characteristics (often negative) to others. These simplified identities are appealing because they reduce cognitive load and help us make quick assessments about others. But they also restrict us from seeing the full complexity of each person.

The lazy ape

We’re wired to be energy efficient.

Our brains comprise only 2% of our body weight, but use 25% of the energy we consume. Anyone that’s tracked their calorie consumption with a smart watch will notice that you often use more calories during sleep than when you do during exercise. Your brain is a hungry organ.

But it evolved in a time of scarcity and has remained unchanged since. That wiring is designed for calorie-deficit, hand-to-mouth, life-on-the-savannah existence and our biases act as mental shortcuts that help conserve energy.

Conscious cognition takes effort. It’s why you feel exhausted when you spend a day active listening, problem solving and other energy-intensive activities. This is why we tend to simplify and categorise; Stereotyping is a type of cognitive efficiency mechanism (Macrae et al., 1996). The lure of energy-efficient simple heuristics – the use of cognitive shortcuts that omit the full analytical and objective processing of information – draws us towards labels and can lead to out-group homogeneity bias.

This bias describes our tendency to believe that members of a group we are not part of (the out-group) are more similar to each other than the members of your own group. It’s the view that they (the out-group) are alike, whilst we (the in-group) are diverse and complex.

Statements, articles and headlines that suggest “Gen Z Won’t Work 9-to-5” or “Millennials Are Killing X Industry” reinforce this bias and its bedfellow affinity bias, and we seek out supporting evidence through confirmation bias. But whilst generational similarities and trends might appear in some data, they often disappear when we control for other variables like life stage, economic conditions, or individual traits (Lyon & Kuron, 2014).

This interplay of social identity, cognitive efficiency, and group dynamics makes generational stereotyping feel intuitive. But intuition is not the same as accuracy; when stereotypes shape hiring, promotion, or development practices, they shift from being misleading to being potentially damaging.

These stereotypes are not always negative. However, studies on stereotype threat can be adapted to show that even positive stereotypes (e.g., “Boomers are loyal”) can pressure individuals into unhealthy behaviours (overwork, fear of asking for flexibility, etc).

If age-based shortcuts limit potential, what does it look like when we meet individuals without these filters? While cognitive efficiency explains why stereotypes are tempting, their consequences in the workplace go far beyond innocent shortcuts. Whilst these shortcuts are natural, they can become problematic in real-world contexts like hiring and development.

The Risks of Age-Based Thinking

Worse, this kind of thinking risks crossing into the territory of age stereotyping – something that, if done along lines of race or disability, would be immediately recognised as discriminatory.

Age is a protected characteristic under many legal frameworks, and stereotyping based on it can cause real harm: limiting opportunities, reinforcing biases, and diminishing the individuality of each employee. If you’re comfortable stating that “Gen Z need to be treated differently in interviews”, consider if you would be as comfortable changing “Gen Z” for “People with disabilities”, “Muslims” or “Married people”.

Vesuvius Pls – a UK ceramics company – discovered this the expensive way. A 2024 tribunal awarded £3.2 million to Glenn Cowie, a 58-year-old engineering manager, when it was found that he was unfairly dismissed and replaced by a younger employee after the company implemented a policy discouraging the hiring of individuals over the age of 45. This policy was part of an initiative to infuse “fresh blood” into the organisation. Cowie had been referred to as an “old fossil” and was told he didn’t know how to manage millennials. The tribunal found this was ‘very close’ to an outright ban on hiring older individuals, which is unlawful in the UK and highlights the legal risks associated with age-based thinking in organisational policies (Personnel Today, 2024).

Beyond legal considerations, it also creates a narrower, less flexible organisational culture; one less able to adapt to the true variety of human experience. Studies suggest that age-based stereotyping can result in the loss of valuable, experienced employees, and reduce organisational competitiveness and agility.

Hippel et al. (2013) examined how age-based stereotype threat affects older employees’ job attitudes and intentions to resign. The study found that older workers who perceive age-related stereotypes in the workplace experience more negative job attitudes and poorer work mental health, leading to increased intentions to resign or retire.

Another study by Chiesa et al. (2019) investigated the impact on older worker’s psychological engagement and attitudes toward development opportunities. This study revealed that such stereotypes are associated with low identification with the company, leading to decreased engagement and interest in development opportunities among older employees.

The evidence is clear: Age-based shortcuts limit potential and can lead to legal ramifications.  

Of course, broad generational trends may emerge in marketing or consumer data. But just as we wouldn’t craft product strategies based solely on astrology signs, we shouldn’t base management decisions on birth decades. While useful in aggregate for identifying broad trends, they can be harmful when applied to individuals.

So, what happens when we look past these filters entirely?

A Better Approach to Individual Differences

In celebrating birthdays, we acknowledge not just the passing of time, but the uniqueness of each person’s story. Organisations could benefit from a similar mindset: meeting individuals as they are, rather than as representatives of a category.

This does not mean ignoring trends or research altogether. It means holding broad patterns lightly, and leading with curiosity; recognising that motivations, values, and working styles are shaped by a far richer tapestry than simple generational shorthand can capture.

For example, Deloitte has been at the forefront of transforming talent development strategies by moving away from traditional generational models, adopting a more personalised approach that considers individual behaviours, values, and attitudes.

By focusing on the specific skills and capabilities of their workforce, Deloitte has moved beyond rigid job descriptions, allowing for greater flexibility and adaptability in work assignments. This approach not only empowers employees to leverage their strengths but also enables the organisation to respond more swiftly to changing business needs (Anoshiravani, 2023; Moody, 2022).

Additionally, Deloitte has invested in mentorship and sponsorship programs tailored to support diverse professionals at various career stages. Programs like Launch, Guide, Compass, and Springboard provide cohort-based experiences that offer guidance, peer connection, and access to senior leaders.

This approach considers the life-stage of an individual. Rather than assume all 25-year-olds are digital natives or all 60-year-olds are resistant to change, life-stage approaches consider factors like caregiving responsibilities, recent career changes, or long-term health conditions. This enables tailored support across the lifespan – whether someone is mid-career and seeking meaning, or later-career and interested in legacy-building and mentorship.

This is a more personalised development approach that enhances employee engagement and satisfaction, as people thrive when their autonomy, competence, and relatedness are supported.

Browsing the Library

In reality, no one walks into a library seeking only books from a particular decade. We search for stories that move us, ideas that challenge us, wisdom that fits who we are now or who we hope to become.

Perhaps in organisations, too, it is time to stop managing by date of birth, and start leading with curiosity; seeking the people behind the labels, and the possibilities within them.

Because every book, like every person, is part of a living story. These stories are not defined by the year they began, but by how they continue to unfold. Organisations that recognise this create more than just productive workplaces; they nurture cultures where individuals are seen, heard, and valued for who they truly are.

When we stop fixating on the spine label (e.g., “1990s,” “Boomer,” “Gen Z”), we begin to engage with the content. We listen more deeply, learn more generously, and lead more humanely.

In doing so, we don’t just build better teams; we build libraries that are diverse, complex, full of possibility, and worth wandering in.

And maybe that’s the point. Not to sort the shelves more neatly, but to remain curious enough to keep turning the page.

References

Anoshiravani, A. (2023). Cultivating the next generation of leaders at Deloitte. Forbes. https://www.forbes.com/sites/gradsoflife/2023/05/31/cultivating-the-next-generation-of-leaders-at-deloitte/

Chiesa, R., Zaniboni, S., Guglielmi, D., & Vignoli, M. (2019). Coping with negative stereotypes toward older workers: Organizational and work-related outcomes. Frontiers in Psychology, 10, 649.

Fraga, M. F., Ballestar, E., Paz, M. F., Ropero, S., & Setién, F. (2005). Epigenetic differences arise during the lifetime of monozygotic twins. Proceedings of the National Academy of Sciences, 102(30), 10604–10609. https://doi.org/10.1073/pnas.0500398102

von Hippel, C., Kalokerinos, E. K., & Henry, J. D. (2013). Stereotype threat among older employees: relationship with job attitudes and turnover intentions. Psychology and aging, 28(1), 17.

Lyons, S., & Kuron, L. (2014). Generational differences in the workplace: A review of the evidence and directions for future research. Journal of organizational behavior, 35(S1), S139-S157.

Macrae, C. N., Stangor, C., & Hewstone, M. (Eds.). (1996). Stereotypes and stereotyping. Guilford Press.

Moody, K. (2022). Skills-first employers may outperform peers, but many are struggling to adapt. HR Dive. https://www.hrdive.com/news/skills-first-employers-may-outperform-their-peers-but-many-are-struggling/632728/

Personnel Today (2024). Overtly ageist employers pay the price for such blinkered thinking. Personnel Today. https://www.personneltoday.com/hr/overtly-ageist-employers-pay-the-price-for-such-blinkered-thinking/

Plomin, R., DeFries, J. C., & Loehlin, J. C. (1977). Genotype-environment interaction and correlation in the analysis of human behavior. Psychological Bulletin, 84(2), 309–322. https://doi.org/10.1037/0033-2909.84.2.309

Tajfel, H., & Turner, J. C. (1979). An integrative theory of intergroup conflict. The social psychology of intergroup relations, 33(47), 74.