Many men worry about the size of their penis - haunted by the size of the boat/motion of the ocean debate - but it turns out they may be putting their measuring tape in the wrong place.
Recent research suggests that size really does matter in the bedroom - but rather than focusing on the crotch, men should be more concerned about their shirt collar size.
The study reveals that men with a neck circumference of more than 16.3 inches (41 cm) are more likely to suffer from erectile dysfunction (ED).
Erectile dysfunction is the most common male sexual problem worldwide and affects nearly half of men between 40 and 70.
The study, which tested more than 90 men aged between 40 and 60, showed those with wide necks were more likely to suffer from metabolic syndrome - a combination of high blood pressure, diabetes and obesity - which can affect sexual performance.
In the medical journal Andrologia scientists from the University School said: “Neck circumference may be a new component of metabolic syndrome in ED. We suggest that neck circumferences of 16.3 inches and over may predict ED in patients with metabolic syndrome."