There is an old song and phrase, “He’s not heavy; he’s my brother.” As warm and inspiring as those six words are, many have found that, in the entrepreneurial world, carrying brothers can be very heavy indeed.

So can carrying parents, sisters, children, and even spouses when family members try to mix business with family. While we all may know of exceptions where family members do work in harmony in a business setting, the majority do not work well, especially as the second generations get involved.

The main reason, in my mind, that they do not work is because most family relationships are based on very different principles and communication styles than are commonly used in running businesses.

For example, many of us have been taught that we should show unconditional love towards everyone in our family. That is, we love and care for one another almost without regard for what has been done, said, or experienced. While this method may work in most functional families, I do not believe unconditional love will work in most business environments.

For example, your brother tells you he will ship a product to your most important customer, then he gets busy and forgets. Two days later, your customer is threatening to take his business elsewhere. What do you say to your brother, especially if he is your full partner?

In the business climate, there must be accountability between coworkers and partners regardless of who is related to whom.

A business consultant for Salt Lake City’s Ernst and Young once told me that family businesses fail at an even higher rate than most small businesses. He said family businesses don’t usually fail because of competition, taxation, or technological changes. They fail because of unresolved family conflicts in the business.

In order for families to be healthy, relatives must focus inwardly on relationships with one another. Businesses, on the other hand, need to focus outwardly on customer relationships, competition, and markets. Admittedly, relationships are important with fellow employees, but the bigger issues lie in the survival of the business itself.

Families often attempt to reward each member equally, but that won’t work in business because employees should be rewarded according to performance, abilities, and contributions to the company mission and the bottom line.

Successful businesses are run according to systems, logic-based decisions, and what is best for the future of the enterprise. In other words, successful businesses are determined by left-brained thinking. Families require more right-brained usage; what feels right is more the rule in families rather than what makes good business sense. Pay raises, promotions, and new responsibilities in a business are usually based on evaluations, while family relationships are not based on evaluating one another. Members of families should treat each other as equals.

Family members tolerate one another and often hire one another because of birth and marriage. Businesses hire employees based on experience, competency, and performance.

In my experience, owning and operating businesses presents many challenges that require great skill and luck to overcome. Mix in the family, and these challenges are generally multiplied and compounded, both in the business and in the family.

“Brotherly love” should be eternal. Businesses are not. Why mix eternal relationships with temporary, earthly ones?

Comments are welcome at [email protected]. Stephen W. Gibson is the Founder of the Academy for Creating Enterprise, a global non-profit that helps people raise themselves out of poverty. You can visit the website here The Academy.