Why does my iphone5 receive text messages twice?

When my iphone5 is on the lock screen and I receive text messages, unless I respond or look at it right away I will receive the same text message a minute later. Does this happen to everyone? How can I turn this off? It's very annoying!

It is just a secondary notification. Many times i don't feel the text the first time it vibrates so apple designed the software to send a second vibration or ring a few minutes later if the message is not looked at the first time. To turn it off, go to Settings>notification center>messages>then scroll down to repeat alerts and change it from once to never.

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