In group discussions, debates about issues are informal and sometimes fast-moving. They can move so quickly that the group's members don't realize that they have reached incorrect conclusions. When this happens, one or more rhetorical fallacies probably played a role — accidentally or intentionally inserted by one of the group's members.
A structure on the Mississippi River, built by the US Army Corps of Engineers (USACE), and known as the Old River Control Structure. It's part of a complex whose purpose is controlling the flow from the Mississippi into a distributary known as the Atchafalaya River. Were it not for this facility, the Mississippi would long ago have rerouted itself into the Atchafalaya, which has a much steeper gradient to the ocean. Since that change would have deprived New Orleans and all the industrial facilities along the lower Mississippi of access to the water and navigational channels they now enjoy, USACE maintains a complex of flow control facilities to prevent nature taking its course. But this project, together with a multitude of levees, dredging projects, and gates throughout lower Louisiana, has had unintended consequences, including erosion of the Louisiana shoreline at the rate of 50 square miles per year. The entirety of the intervention can be viewed as an example of the Fallacy of Composition: even though each element of the whole intervention makes sense, the whole of the result might not. For more about Atchafalaya, see the famous article by John McPhee, which appeared in the February 23, 1987, issue of The New Yorker. Photo by Michael Maples, courtesy U.S. Army Corps of Engineers.
Because of its subtlety, the Fallacy of Composition is a favorite of those who intentionally use rhetorical fallacies. When people use the Fallacy of Composition, they make statements about some parts of a whole (or even every part of a whole), and then conclude something about the whole. To illustrate the use of the fallacy, here's a particularly transparent form, just to give you the idea of how it works:
Since the global economy is in recession, and our jobs are less secure than they once were, everyone should pay off their debts and increase the fraction of their income that they save.
If we were to follow this advice, the recession would quickly become a depression, because economic activity would contract severely. Although the statement is probably true for individuals, the conclusion about the entirety of all individuals is false.
The Fallacy of Composition also occurs in group discussions about managing projects:
We can make up some time and get closer to the original schedule if Tim and Ellen work through the weekend. So it's probably best if everyone works every weekend for the rest of the project.
If we take this approach, people will become fatigued, their work quality will degrade, some will seek reassignment, and the project might never complete.
Here's an example in which an approval board finds two issues in a proposal, and then rejects the entirety on that basis:
We've found serious problems in the proposal. The Localization budget is too low, and the schedule for customer extensions is too aggressive. You need to rethink the whole thing.
The above Because of its subtlety,
the Fallacy of Composition
is a favorite of those
who intentionally use
rhetorical fallaciescomment omits any proof that the two flaws cited are justification for the final recommendation.
And from Glen's performance review:
I'm sorry I couldn't recommend you for a promotion this year. You had some trouble working with Fran, and there were also problems with Leo. You need to learn how to work better with people.
Perhaps the conclusion above is correct, but two difficult relationships are probably not adequate proof. For instance, if both Fran and Leo have problems with everyone, perhaps the problem isn't Glen's. This application of the Fallacy of Composition offers a convenient alternative to justifying decisions made for other reasons.
One important distinction between a Fallacy of Composition and valid inductive reasoning is the nature of the generalization. An inductive argument contains a proof of its generalization; a fallacy of composition merely suggests its generalization. It is the subtlety of this distinction that makes the Fallacy of Composition so difficult to identify in the moment. 
Top 
Next Issue
Do you spend your days scurrying from meeting to meeting? Do you ever wonder if all these meetings are really necessary? (They aren't) Or whether there isn't some better way to get this work done? (There is) Read 101 Tips for Effective Meetings to learn how to make meetings much more productive and less stressful — and a lot more rare. Order Now!
Your comments are welcome
Would you like to see your comments posted here? rbrenaXXxGCwVgbgLZDuRner@ChacDjdMAATPdDNJnrSwoCanyon.comSend me your comments by email, or by Web form.About Point Lookout
Thank you for reading this article. I hope you enjoyed it and
found it useful, and that you'll consider recommending it to a friend.
This article in its entirety was written by a human being. No machine intelligence was involved in any way.
Point Lookout is a free weekly email newsletter. Browse the archive of past issues. Subscribe for free.
Support Point Lookout by joining the Friends of Point Lookout, as an individual or as an organization.
Do you face a complex interpersonal situation? Send it in, anonymously if you like, and I'll give you my two cents.
Related articles
More articles on Effective Meetings:
The Perils of Piecemeal Analysis: Group Dynamics- When a team relies on group discussion alone to evaluate proposals for the latest show-stopping near-disaster,
it exposes itself to the risk that perfectly sound proposals might be inappropriately rejected. The
source of some of this risk is the nature of group discussion.
The End-to-End Cost of Meetings: I- By now, most of us realize how expensive meetings are. Um, well, maybe not. Here's a look at some of
the most-often overlooked costs of meetings.
Allocating Airtime: I- The problem of people who dominate meetings is so serious that we've even devised processes intended
to more fairly allocate speaking time. What's happening here?
Dealing with Meeting Hijackings- When you haven't prevented a meeting hijacking, and you believe a hijacking is underway, what can you
do? How can you regain control?
Issues-Only Team Meetings- Time spent in regular meetings is productive to the extent that it moves the team closer to its objectives.
Because uncovering and clarifying issues is more productive than distributing information or listening
to status reports, issues-only team meetings focus energy where it will help most.
See also Effective Meetings for more related articles.
Forthcoming issues of Point Lookout
Coming July 23: Microdelegation- Microdelegation is a style of delegation in which the delegator unintentionally communicates the task to the subordinate in such detail and so repetitively that the subordinate is offended. As a result of this delegation style, many subordinates feel distrusted or suspected of fraud or goldbricking. Available here and by RSS on July 23.
And on July 30: What the Dunning-Kruger Effect Actually Is- Although the Dunning-Kruger Effect is widely recognized, people describe it — and understand it — in many different ways. Some of these expressions are misleading. Proceed with caution. Available here and by RSS on July 30.
Coaching services
I offer email and telephone coaching at both corporate and individual rates. Contact Rick for details at rbrenaXXxGCwVgbgLZDuRner@ChacDjdMAATPdDNJnrSwoCanyon.com or (650) 787-6475, or toll-free in the continental US at (866) 378-5470.
Get the ebook!
Past issues of Point Lookout are available in six ebooks:
- Get 2001-2 in Geese Don't Land on Twigs (PDF, )
- Get 2003-4 in Why Dogs Wag (PDF, )
- Get 2005-6 in Loopy Things We Do (PDF, )
- Get 2007-8 in Things We Believe That Maybe Aren't So True (PDF, )
- Get 2009-10 in The Questions Not Asked (PDF, )
- Get all of the first twelve years (2001-2012) in The Collected Issues of Point Lookout (PDF, )
Are you a writer, editor or publisher on deadline? Are you looking for an article that will get people talking and get compliments flying your way? You can have 500-1000 words in your inbox in one hour. License any article from this Web site. More info
Follow Rick
Recommend this issue to a friend
Send an email message to a friend
rbrenaXXxGCwVgbgLZDuRner@ChacDjdMAATPdDNJnrSwoCanyon.comSend a message to Rick
A Tip A Day feed
Point Lookout weekly feed
My blog, Technical Debt for Policymakers, offers
resources, insights, and conversations of interest to policymakers who are concerned with managing
technical debt within their organizations. Get the millstone of technical debt off the neck of your
organization!
Bad boss, long commute, troubling ethical questions, hateful colleague? Learn what we can do when we
love the work but not the job.Learn how to make your virtual global team sing.Are you managing a change effort that faces rampant cynicism, passive non-cooperation, or
maybe even outright revolt?Learn how to make meetings more productive — and more rare.