Our workplace shows us a snapshot of society. It includes sons and daughters, mothers and fathers, boyfriends and girlfriends; all with their own stories.

These characters make up the hum of our working lives, animating each day with their individuality. We appreciate this diversity because it’s the core of our work experience, not a supplement. Indeed, our business decisions are improved when we embrace contrasting perspectives.

In our colleagues’ stories, the workplace reflects our society’s conventions, both good and bad. For over a century, marginalised minorities across the world have been campaigning for equal treatment in their personal and professional lives.

Last month, 379 companies, including Twitter, added their names to an amicus brief submitted to the United States Supreme Court in support of marriage equality. Here in Twitter’s European headquarters in Dublin, many of our employees – gay and straight, Irish and non-Irish – are involved in the movement for a Yes vote on May 22nd.

That this issue has attracted so much support in our office speaks not only to the culture of inclusion at Twitter but also to the larger business case for Yes.

As I see it, this case has three key elements. First, people perform better in the long run when they can be themselves. Second, talent is attracted to organisations which demonstrate an appreciation for diversity, inclusiveness and equality. Finally, Ireland’s international reputation as a good place to do business will be enhanced by a Yes vote.

One of my roles as a leader is to create an environment in which people can do their best work. Individuals perform better when they feel respected and supported. For many lesbian and gay employees, coming out to colleagues is an important aspect of being themselves, although when and how to do so is their choice. The acceptance of marriage equality can only diminish the anxiety that may attach to coming out, improving the workplace for countless people.

When I first visited Silicon Valley I was stunned by what I saw. Job titles, offices and dress codes seemed to matter less than ideas and results. I found that culture very appealing and wanted to be part of it, so I spent the following decade working for US tech companies such as Google and Twitter.

No company is perfect and we in Twitter certainly have a lot more to do, but we would like to be known as a place that cherishes diversity and treats all of our employees equally. To attract and retain those employees, the country that hosts our office must offer an equally embracing culture.

Furthermore, to attract talent to our shores we must first have the right companies here. In 2013, Forbes ranked Ireland as the best country in the world for business. The IDA notes that we are ranked first for availability of skilled labour. These accolades have been hard-won over several decades during which our national reputation was transformed.

Once an inward-looking island nation, we’ve become a modern society with global vision. Foreign direct investment (FDI) is now a pillar of our national economic strategy. But in a hard-fought market for globally mobile FDI, we must be competitive on many fronts. When pitching Ireland to international business, the case is more easily made when we can point to a society that has open and inclusive values.

Where a company chooses to do business shapes the way it is perceived by employees and customers alike. Twitter is supporting a Yes vote because we want Ireland to be in the group of nations that has taken this step, those that champion equality of treatment and reject the repetition of a history best forgotten. We encourage other companies to do likewise.

For my own part, I was the youngest in a big family and as a teenager I discovered that one of my brothers, Brian, was gay. According to him, while our family was supportive, our country was much less so – Ireland in the 1980s was no place to be different.

As we move to the next generation, I want to believe that things have changed.

I am married with two young sons. If one of my boys turns out to be gay, I would love and support him without condition. I hope my country would do the same.

Stephen McIntyre is Twitter vice-president, EMEA Sales and MD, Ireland. He is speaking at a Glen business breakfast in Dublin this morning