No, I'm not talking about an outward physical trait. What I'm addressing here is the size of a few things that are far more important. How "big" is your heart? How "broad" is your mind?
Living with a "big heart" and a "broad mind" enables you to spread good energy, see things in a more accepting manner, and allows you to learn more easily. A "narrow mind" and "closed heart" tends to drive people, who may add texture, love, and kindness, to your life...away. What you are left with are only those with the same "closed heart" perspective and "narrow mindset" as yourself. That will, most assuredly, limit your view of life and will stunt your ability to grow as well.
However, the toughest part is to be able to admit to yourself that you have a "closed heart" and a "narrow mind." It takes a lot of intestinal fortitude to recognize one's shortcomings. And...even more to want to change. A "broad, or open, mind" and a "big heart" may cause a person discomfort at first because it goes against what one has "stood for" his or her entire life. Yet...once they are achieved a person frees himself, or herself, from the negative energy and the physical affects that a "small heart" and a "narrow mind" causes.
If you've ever be around negative people (or you are one yourself), their faces emit the affects that their negativity creates. A positive person is lighter, happier, and less stressed. Closing one's heart and one's mind will, ultimately, increase one's stress and also cause physical ailments.
So...be aware of the "size" of your heart and mind. Open them both. It will allow you the freedom to pass on an overly stressful and judgmental life. And - give you the rewards that go with a "big heart" and a "broad mind."