According to psychologists at South University, the psychology of gift-giving during the holidays is complex. It is a way to express feelings of love, connect with another person and reinforce appreciation, but it can also trigger feelings of guilt or resentment -- particularly if a gift is a lot more or a lot less than what was expected. The right Christmas gift to show your girlfriend that she's special is one that is very thoughtful, personal and demonstrates that you care. The wrong gift is one that took little thought or effort -- or one that simply doesn't make sense for her.

Gift Certificates Or Cards

It doesn't get more impersonal than a gift card.
It doesn't get more impersonal than a gift card.

Anyone who buys a gift certificate or card is basically saying, "I don't know you well enough to pick something out for you myself." That's not exactly heart-warming for someone you're crazy about. If your intention is to send your girlfriend on a shopping spree -- which she may like -- give her some cash on a different occasion. An exception to the gift certificate rule would be to buy her an experience she wouldn't normally get herself -- like a spa or beauty treatment package -- or something you can share together, like a trip to a theme park.

The Wrong Jewelry

Unless you're getting her a certain ring she wants, proceed with caution.
Unless you're getting her a certain ring she wants, proceed with caution.

Not all jewelry is a bad idea, but proceed very carefully. If you get something too expensive too soon in the relationship, it may freak her out. If you get something cheap, it communicates that you're cheap. If you get something that is very classy but she's expecting an engagement ring instead, she won't be very happy. You also run the risk of buying her something that really isn't her style. On the other hand, you can score big with the right jewelry. If you go the jewelry route, do your homework -- get some help from her best friends.

Workout Gear

It may be better to let her get her gear on her own.
It may be better to let her get her gear on her own.

You might not intend to insult her, but getting your girlfriend workout equipment or apparel sends the subtle message that she needs to get into better shape. Even if she wants to work out more, a Christmas gift is not the appropriate way to encourage her.

Household and Kitchen Appliances

A blender isn't the best way to show love.
A blender isn't the best way to show love.

Even if your girlfriend idolizes cooking show celebrities, you're probably better off steering away from anything that communicates about her role in the house and kitchen. Leave those types of gifts to her friends and family members. Although she might really like the latest kitchen gadget, it just isn't romantic coming from you.

Anything Vulgar

Your girlfriend might have a great sense of humor, but don't get her anything gross for Christmas. That includes any vulgar version of yourself or your body parts. Not only is it inappropriate and immature, it says that you don't take her or the relationship seriously enough to do something more thoughtful.

Clothes, Clothes, Clothes

You might be in trouble if those clothes don't fit.
You might be in trouble if those clothes don't fit.

A lot of women like to expand their wardrobes when given the opportunity, but you set yourself up for potential failure with clothing as a Christmas gift. Just because it looked great on the rack doesn't mean it will fit well and flatter her -- and you may end up inadvertently highlighting some of her insecurities. If you want to get her some apparel, get an item that means something to her personally -- like a jersey from her favorite sports team, or that scarf she's been eying.

Live Animals

An animal can be very awkward as the wrong gift.
An animal can be very awkward as the wrong gift.

With the exception of fish, pets are a serious commitment. Even if your girlfriend is an animal-lover, you're better off going shopping for a new puppy together on a different occasion. That way she's making the commitment for herself.

Stuffed Animals

Save it for a child.
Save it for a child.

You girlfriend isn't nine years old. A stuffed animal might look cute in a Christmas bow, but it's just going to sit collecting dust -- reminding her that you are incapable of buying a more thoughtful, useful gift.

Electronic Items

While your girlfriend might be high-tech, the problem with most electronics is that they aren't very thoughtful or personal. Exceptions would be devices loaded with some special songs, videos or photos. Otherwise, unless she asks you for or hints at a very specific item, or you know that she dying to get her hands on the latest upgrade, avoid electronics.

Anything Secretly For You

Buying your girlfriend something that is more for your benefit comes across as selfish. Tickets to your favorite band's concert or a copy of your favorite movie are not what she wants. Be thoughtful and get something that she adores, even if you loathe it.