A huge Yahoo Email study was recently conducted by Yahoo Labs and Cornell University. The study had important findings for the ways that age, gender, and type of device effect Email Response behavior.

The researchers analyzed over 16 billion Email messages sent by Yahoo Email. Based on the sheer number of Email messages analyzed, this made this study the largest of its type to date.

The researchers tracked Emails over the course of several months and analyzed key information. The goal was to try to determine the key Email patterns and habits of the participants.

Key Yahoo Email Study data analyzed:

Subject lines
Time of day
Message length
Presence (or absence) of attachments
Age and gender of the senders and recipients
Type of device (desktop, tablet, smartphone)

The study focused on “reciprocal interactions”, or the replying behavior in pairs of users. Each user needed to exchange at least 5 replies in each direction over the course of the study.

“We focus our analyses on replying behavior in dyadic interactions, i.e., conversations between pairs of users.”

— Study Authors

This narrowed down the study to (a still impressive) 2 Million unique users exchanging 187 Million Email messages over several months.

The Yahoo Email Study also tried to focus only on “human exchanges” of messages. To accomplish this, the researchers tried to exclude S pam Email, social network notifications, and other automated emails.

The study also was limited to commercial Email domains and excluded personal Email messages.

So, what are the Yahoo Email Study Results?

It resulted in some surprising, as well as some unsurprising, results.

Age Effects your Email Behavior:

The Yahoo Email study found some interesting differences in Email behavior based on your age.

Younger users have the fastest reply times compared to older Emailers (13 minutes for teens, 24 mins for adults, and 47 mins for mature adults).
And younger Emailers also use shorter replies compared to older users (17 words for teens, 31 words for adults, and 40 words for mature adults).
And young people respond to more Emails in total then older people.

“Although we found no significant variation due to gender, we find that younger email users reply faster and write shorter replies than older users.”

So, the younger you are, the quicker you respond to Email, and the more of it you respond to.

Almost no differences between Men and Women:

The study found almost no differences between men and women in Email behaviors.

Men responded just a bit quicker to Email messages than women (24 minutes for men, 28 minutes for women).
Men also responded with fewer words in their messages then women (28 words for men, 30 for women).

So, the Email differences between men and women was small and not very significant.

Response is different from a computer vs a smartphone:

Email behavior is different when responding with smartphones compared to desktop Email clients.

Those on smartphones responded quickest (28 minutes using smartphones, 57 minutes on a tablet, and 62 minutes on a desktop).
And smartphone replies were the shortest (20 words on a smartphone, 27 words on a tablet, and 60 words on desktops).

So, when using a smartphone, you respond the quickest, but the messages are also the shortest.

Next, the researchers looked at how Email Overload impacts Email behavior!

Some users were categorized into either “high” or “low” Email Overload levels based on their Email volumes being much higher (or lower) compared to the average user in the study population.

The Yahoo Email study found that those in the "high" Email Overload group had much higher processing activity of both messages sent and responses made.

But the efforts of those suffering from Email Overload wasn’t always successful.

“While users increase their activity with higher email load, it appears that they are not able to adequately compensate for the increased load.”

High volumes result in low responses and short Emails:

Those receiving the most Email spent the most time processing messages in their Inbox.

Those that receive high volumes of Emails only respond to 5% of them each day, compared with a 25% response rate for those with lower Email loads.
And for the high volume Emailers, their responses were shorter than those that receive lower levels of Email.

So reply time decreases as load increases, and the length of the reply also decreases.

Age, not gender, plays a role in Email Overload:

For high-volume Emailers, younger people are a bit better at keeping up with their Email than older people.
Although the younger group also tended to reply with shorter messages.
Surprisingly, there was almost no difference to higher Email load levels based on gender.

“Email Overload becomes progressively worse for older age groups”

So, younger users respond faster but with shorter messages, whereas older users keep their longer responses, but just respond to less messages. And gender doesn’t have an impact when it comes to Email volumes.

In threaded messages, responses are initially similar:

Threaded Email messages are where you respond in a “back-and-forth” manner to another person.

At first, the length of an Email response will “match” the sender's response time and length.
Over time, the messages in the "thread" become less similar.
Replies get longer as the thread progresses.
Except for the last message response, which is often very short.
And replies start fast, but then slow down significantly over time.

And longer conversations tend to have faster response times and shorter responses.

We still respond to messages very quickly:

Most people respond very quickly to their Email messages.

Nearly 90% respond within one day.
Almost half respond within 47 minutes.
And 2 minutes is the most frequent response time.

So, we are still responding to Emails very quickly - many in just minutes, and nearly all within the day.

We tend to respond briefly to most messages:

Most email responses are on the short side.

The most frequent length is a very short five words.
And a significant amount (almost half) are under 43 words in length.
But 30% of Email messages are 100 words or longer.

So, most messages are short, but a good percent (30%) are much longer.

Response times were fastest during the work day:

Response times followed some expected results based on the time of day and day of the week.

As expected, response times were fastest during the work day.
Response times slow down significantly during the evenings and weekends, when the replies also become shorter and briefer.
And response time is longest in the morning compared to the afternoon or evening.

So, Emailers were more responsive during the day then in the off-hours and weekends, when responses were slower and messages shorter. And the longest Emails are written in the morning.

Adding an attachment really slows things down:

Attachments have a big impact on Email message response time and length.

Responses to messages with attachments took much longer (56 minutes with an attachment, almost double the 32 minute response without attachments).
And adding an attachment results in a longer response )(47 words with an attachment, 33 words without attachments).

So, not surprisingly, Emails with attachments results in a slower, and longer, Email response.

Email is the most widely used business communication media and used for many purposes beyond just simple communication.

But it is still a relatively new media, which is why the authors were so interested in studying such a large sample of Email message data.

“While email accounts for a considerable portion of interpersonal communication, emailing behavior is not well understood.”

What is especially important about the Yahoo Email study (beyond the incredible size of the sample), is that it focused on the quantitative measures of Email Overload.

This is in contrast to many other Email studies which look more at the qualitative and perceptional aspects of Email Overload.

The Yahoo Email Study had some very important and interesting findings. I tried to focus on the key items that I thought would be of most interest to everyone.

If you are interested, you can download the entire research study, Evolution of Conversations in the Age of Email Overload, from Cornell University.