If you ask what is the most important thing in the life of a Frenchman, a holiday is definitely the first place that cannot be beaten. What is the purpose of work, of course, it is to make money on vacation. When a vacation is over, it's time to start planning for the next one. In the summer, the whole company is empty, which is the norm for the French. 
As a result, a French doctor recently poured cold water on all French people. On January 27, French doctor Frédéric Saldmann celebrated the publication of his new book, "Your Future Is Determined by the Prescription" ("Votre **Enir sur Ordonnance") and France 2's "What a good time!" 》（quelle époque!Show as a guest. 
In a discussion with host Léa Salamé, the fasting cardiologist and nutritionist suggested tips for boosting IQs: fasting, not sleeping and not taking too long vacations. It was also on this show that he made ** remarks:If you're on vacation for more than three weeks, your IQ drops by 20 points! 
One can imagine what kind of uproar his remarks caused on social networks. What's more, this is still in France, where something starts to complain and taunt skills first. "So doctors, what will we become when we retire? ”
"With just 15 weeks of vacation, you can go from 100 to 0 in IQ. ”
"Then doctor, you must be on vacation a lot, haha. ”
And so on and so forth......Faced with overwhelming negative reviews, Frederick explained: "I came to my conclusions based on a study in Germany. The study involved 120 people between the ages of 20 and 60 who underwent an IQ test before and after a vacation to judge the change in IQ from a vacation. The conclusions of the study show that the loss of IQ is particularly pronounced in people over the age of 40. To substantiate his claims, he also provided the name of the study, the journal in which it was published, and the author: "The Effect of Vacation Length on Cognitive," published in the Journal of Applied Psychology, 94 (2), 375-383, 2009 Performance: A Longitudinal Study by Schwarzer, G, schulz, r., gerst, m.。So here comes the question:There is simply no trace of this study on the Internet. 
The 94th issue of the Journal of Applied Psychology was indeed published in 2009, but it did not publish the article. Pages 371-391 are a completely different article. Even if you search for the author's name, you can't find any relevant studies. One trick doesn't work, Frederick has another trick. He also cites the work of another, more well-known researcher: the German psychologist Siegfriend Lehrl.
There are plenty of news reports online that one of his studies showed that a three-week vacation would lead to a 20-point drop in IQ. Frederick's remarks echo this conclusion. 
Here's the problem: the article, which has been mentioned since at least 2000, is also not available online.
However, the newspaper Libération confirmed the existence of the study in a recent article. Siegfried mentioned the study in another publication: in 1984 entitled "Die Talfahrt des IQ im Krankenhaus" (The Decline of IQ in Hospitals). Unfortunately, despite the existence of the study, it is difficult to verify the conclusions of the study. In this regard, Frederick said: ". .Of course, I also wanted to call ** to ask Lyle for confirmation, but he is dead(Gefred Lyell, died in 2003.) All of them have published books......Is it really okay to quote the source so sloppily......Franck Ramus, an expert in cognitive science and director of research at France's National Center for Scientific Research (CNRS), said Frederick's televised remarks "seem incredulous": "Overall intelligence, as measured by IQ scores, is stable throughout life." Of course, there is a certain amount of error in the test results: there may be a few fluctuations between tests due to test conditions, etc. But I've never seen a 20-point change, and to make such a big change you have to go through brain damage. "However, it is possible that the level of learning will decline after the holidays, which has been scientifically confirmed. 
A study published in 1996 noted that "knowledge test scores decline during the summer vacation" and that "the impact on mathematics is greater, the impact on reading is smaller, and the impact on arithmetic and spelling is greater." Although the drop in grades during the holidays is recognized, it is by no means decisive. It also depends on the student's socio-cultural background and the activities they participate in during the holidays. "Students on summer vacation will have a slight drop in test scores, and they will forget part of what they know," Frank noted. This is a recognized influence. If a decline in academic performance reflects a decline in intelligence, this is roughly equivalent to a drop in IQ score of 15 points. "Well, now the French can go on their vacation. February** Dynamic Incentive Program