A sensible, succinct answer for a change.

(Feel free to blurb that.)

People who are uncomfortable make people around them feel uncomfortable - so it's safe to assume she's feeling uncomfortable. I've never heard of the 'laugh so hard it's inappropriate' route to ruthless success. This is making her look like an idiot and no doubt she feels like one too. OR, she's simply oblivious, like the woman with the terrible laugh in Sleepless in Seattle who the Tom Hanks character dated before he met the Meg Ryan character. The audience was set up to hate her with That Laugh.

If I were the LW I would be as reassuring, as grounded, as quiet and sober as possible when dealing with this person. In fact, have the opposite of humour - ask if you have said something unintentionally funny next time she laughs. Play the dead bat approach to see if that can't take some of the wind out of her billowing sails.

I also think it would be doable to have a 'state of the union' chat with her. Ask her how things are going. Is she feeling comfortable etc. Then say that for your part you sometimes are surprised by her laughter. If she has any sensitivity this should be enough.

Otherwise - like Cary says - you can't have someone around you all the time who makes you uncomfortable. She'll have to change or go.

Thinking of which - a woman I went to uni with got really far down the track for a TV journlism apprenticeship. When she didn't get it she asked for feedback and they said 'frankly, it's you personality. We don't like you.'

Now she's a government minister. Makes you think ...

usually i agree with his advice, but this time i think he was way over the top. clearly some eager beaver with a similarly over-enthusiastic personality hurt him or someone he knows in a big way. but that's not your problem right now, is it? you simply need a way to get this poor girl to mellow her shit before she makes an ass of herself or you -- without making an ass of her or you in the process.

your letter was full of the exact kind of things you should say to her. take her out for lunch, or even a drink, and gently tell her that you appreciate her enthusiasm, that you think she shows tons of promise, but that she does need to sort of, kind of (i'm very bad at breaking this kind of news, so i'm putting mealy-mouthed me in your shoes) dial it down.

i think we've all known people in social or work situations who are well-meaning but have absolutely no idea how they come off in public. hell, WE may even be people like that. if i were (am?) that annoying, i would certainly appreciate it if someone who clearly cared, as you do, would kindly, gently let me know.

and of course, if she turns out to be the evil conniving bitch cary is afraid she is, THEN you show her the door.

I'm trying to picture this. Are we talking about a nervous giggle, a "please like me" fakey happiness, or derisive stuff that makes you feel disrespected? If it's either of the first two, it's part of her personality and good luck changing it. But if it's the last, you need to call her in and say something like, "I've noticed that you seem to laugh at some things I consider very important. I'm concerned that you may not be understanding that directions I give you have to be taken seriously, and I'm feeling like I can't be sure you're carrying out the work properly because of it." If she thinks your perception of her job performance is tied to her strange laughing reaction, that should sober her up pretty quickly.

P.S. I was once called in to the boss and asked how I could handle a difficult hypothetical challenge. I sat for a moment, giving it some thought, and was told by my boss that my expression was "too morose." He'd probably like your manic girl.

You know, whenever I started a new job, I was a paranoid nut job the first month. I'd laugh too much and at the wrong thing. I was absolutely sure I was doing everything wrong and that everyone saw it. I was also sure that the bosses would figure out they made a big mistake and I would be out the door, forthwith. It just took a while to calm down and get my bearings. Eventually, I just expected it to happen whenever I started a new job and held on for the ride until my anxieties died away and I found my confidence.

Maybe LW, you could do something to help your new employee feel more comfortable. Take her out to lunch, say. And if her laughing continues, you might just want to have a human heart-to-heart and find out why she's doing it and let her know it concerns you a bit. But give her a chance to get acclimated. That may need all she needs. When she starts to feel more comfortable, she may just turn out to be a great assistant.

There's research that shows that people in subservient positions laugh more at jokes told by people in authority positions that by peers. It's probably completely unconscious on her part, reacting to your position of power over her. Maybe narrowing the gulf between manager and subordinate will allow her to feel secure enough to stop the giggles.

Although I did very well in school, it took me years to learn how to be appropriate in the workplace. While I could come up with the discipline, creativity, etc. to ace exams, it was harder for me a few years later to hum along in a semi-corporate environment with all its social norms for 8 hours at a time. Here is an area of life in which certain inequities come into play. Some people are raised in homes, schools, and communities from which it is easier to segueway into that nice assistant job. Other people easily betray the strange burdens and deficits of their particular upbringings until they learn to recognize and compensate for them.

You can really do something for this young woman by fostering her self-awareness and mentoring her in the norms of your workplace. Have her understand how much you want her to succeed--both for herself and for you. Many, many young people have a self-destructive streak. But if you succeed in making her more conscious and enroll her in succeeding, you will have done a great thing for her.