Whether you've gone away to college, moved to a new city or even just traveled for vacation.

Whether you've gone away to college, moved to a new city or even just traveled for vacation, homesickness is a common emotional experience. But what exactly are we feeling when we experience homesickness, why do we feel it so deeply, and why does it sometimes affect us physically?

“Homesickness has everything to do with attachment (依恋)," said Joshua Kiapow, a physically and emotionally," he explained. "We're longing for something that in our minds is known, predictable, consistent and stable."

Of course, different people experience homesickness in different ways. Kiapow said homesickness often causes physical changes in our bodies. "You feel it in your stomach — it' s an unease in which you feel uncomfortable, nervous, anxious, stressed, or tense because you're in a place or situation that's not familiar, that triggers (触发) your "fight-or-flight" response (“战或逃”反应), he said. "It's an evolutionary (进化的), adaptive thing that wires us to protect ourselves from danger when something is unknown. When we think about home, we know that the sense of unknown and potential danger is not happening there, so we want to return."

Meanwhile, longing and sadness also play a big part in feeling homesick. "The comfort of home becomes like a person you've lost and miss," said Kiapow. "You may have some (memories) about home and what you're missing, comparing everything in your day to your experience back home, and that can create a lot of sadness."

So what's the best way to fight homesickness? According to Klapow, keeping yourself busy with activities like schoolwork is a good way to keep your mind focused on other things. "When you're doing an activity, it distracts you, but you're also creating a new reality for yourself," he said. And, most importantly, sharing your feelings with others who are going through the same thing as you are means you have a support network. "Once you feel compassion (同情) from other people in the same place, you tend to feel less homesick," as Klapow said.

Most of us have something about us that we’re not 100% in love with, such as an impulsive streak or a short temper. What if those personality traits (个性特征) could be improved with daily use of a smartphone app? That was the focus of a new study from an international research team led by the University of Zurich.

“Personality traits predict several important aspects of life such as success at work, health and even a long.” says first author Mirjam Stieger. PhD. of Brandeis University in Waltham. Massachusetts. “So we wanted to test whether people can actively shape their personality traits with the help of a digital intervention (干预) within a relatively short period of time.”

Around 1.500 participants were provided with a specially developed smartphone app called PEACH for three months. On the app, a virtual companion communicated with the participants daily and provided support to help them make the changes they desired. And participants were divided into two groups — an intervention group and a waitlist control group. Participants in the waitlist control group selected and indicated their change goals before a one-month waiting period, and then they received the same three-month intervention as the intervention group.

The researchers found that participants in the waitlist control group didn't change their personality traits during the one-month waiting period. but participants who received the intervention reported changes in the desired direction. “We also found that friends and family members were able to detect personality changes,” Stieger says. “Another surprising finding was that most participants were able to maintain (维持) their personality trait changes until three months after the end of the intervention.”

While apps could be used to promote personality change, mental health expert Karen Peters warns, it's important to remember they are there for support and not as a substitute for an individual's change. “The use of an app itself isn't going to influence change — change is influenced by internal motivation.” she says. “The new study demonstrates this point by determining that change outcomes were in agreement with the individual's desire to change.”

You expect wolves to howl (嗥叫) . You know their sound, a long and loud cry, from movies. But you were shocked the first time you heard your pet make a similar sound when it heard a siren (汽笛). You might ask, “Why does my dog howl at sirens?”

For a long time, the explanation was simple: it hurts. Dogs’ hearing is so much more sensitive than ours that a sound that’s just annoying to us must be excruciating for them. However, many dog owners question its validity: when dogs howl at sirens, they don’t appear to be in any pain. Also, most howling dogs don’t appear to be acting fearfully by hiding or shaking as they do with scary sounds such as the noise of thunder.

Canine (犬的) science points us in another direction, to dogs cousins and ancestors, the wolves. For a wolf pack, howling occurs to determine the location of pack members or discourage other animals from approaching. Or, it may be a way to warn the pack about an abnormal situation nearby.

Dogs may be alike in this aspect. If your dog howls at a loud sound, it might be to get your attention. In the case of an emergency vehicle siren or a home alarm, dogs may simply want to make sure you’re aware that a sound that is not usual or expected is occurring so you can do something about it. However, they might howl at the siren, especially one that’s on four wheels, as a way to “drive” it away. If the siren gets further away and therefore makes less noise, your dog will feel like the howling helps to discourage the siren.

So, now you understand your dog’s insistence on howling when it hears sirens or similar sounds-and whether or not the sound is hurting your pet’s ears.

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